<£ fll3r/|.^C? 


v*w * %s 


THE 


QUARTERLY JOURNAL 


OP 


SCIENCE, 
LITERATURE, AND THE ARTS. 


VOLUME XX. 


LONDON: 
JOHN MURRAY, ALBEMARLE-STREET. 

1826. 


Ji 01 


LONDON: 
r«nt«d bj WILLIAM CLOWES, 

Northumberland-court. 


CONTENTS 


OF THE 


QUARTERLY JOURNAL, 

No. XXXIX. 1/ 


ART. PAOfi 

I. On the Means by which Crabs throw off their Claws. By Dr. 

Mac Culloch 1 

II. On the Fogs of the Polar Seas. By George Harvev, Esq., 

F.R.S., L. andE 11 

III. On One of the Causes of the Movements of the Barometer, and 
of the South and West Winds. By Marshall Hall, M.D., 
F.R.S.E, &c. &c 14 

IV. Description of an Instrument for destroying- a Stone in the 
Bladder. By J. B. Griffiths, Esq 21 

V. Outlines of Geology, being the Substance of a Course of Lec- 

tures on that Subject, delivered in the Amphitheatre of the 
Royal Institution of Great Britain, by William Thomas 
Brande, F.R.S., Professor of Chemistry in the Royal In- 
stitution, &c %i 

VI. On a peculiar Appearance exhibited by Hoar Frost. By J. 
Mac Culloch, M.D, F.R.S.E , &c 40 

VII. A Letter from A. Copland Hutchison, Esq., to Sir 
Everard Home, Bart., containing an Account of a successful 
Case of the High Operation for the Stone .... 44 

VIII. On Calcareous Cements. By John White, Esq. . . 50 

IX. Remarks on Phytolacca Dodecandra, or, the Mustard Tree of 
the Scriptures. By John Frost, F.L.S., Member of the 
Royal Institution, &c. . ' . . t i * . 57 


11 CONTENTS. 

ART. PAGE 

X. A Monograph of the Genus Tachyphonus ; a Group of Birds 

belonging to the Tanagrae of Linnaeus. By William Swain- 
son, Esq., F.R. and L.S., &c. 60 

XI. Supplement to a Paper on the Vibrations of Heavy Bodies, in 
the Fifteenth Volume of this Journal. By Davies Gilbert, 
Esq., M.P., Treas. R. S„ &c. 69 

XII. Correction of an Error in the " Meteorological Essays." By 

J. F. Daniell, F.R.S. i . . . . 74 

XIII. On the Barometer. By J. F. Daniell, F.R.S. . . 78 

XIV. Astronomical and Nautical Collections, No. XXIII. 

i. A Method of Computing the Sun's Horizontal Parallax from 
Observations of the Transits of Venus. By T. Henderson, Esq. 94 

ii. Remarks on the Discordances observed between the Lunar 
Observations at Greenwich and Paris. By T. HENDERsoN.Esq. 96 

iii. The Latitude of Greenwich, as computed by Professor Bessel 98 

iv. Bessel's latest Fundamental Catalogue of Stars, deduced 
from his Observations in the last five years. Schum. Nach. No. 78. 99 

v. Abstract of Captain Sabine's Experiments to determine the 
Figure of the Earth. Printed at the expense of the Board of Longi- 
tude, 4to. London, 1825 100 

vi. Extract from a Letter addressed by Professor Bessel to Pro- 
fessor Schumacher, relating to the Greenwich Observations . 108 

XV. Analysis of Scientific Books. 

I. An Attempt to establish the First Principles of Chemistry by 
Experiment. By Thomas Thomson, M.D. Regius Professor of 
Chemistry in the University of Glasgow, F.R.S. Lond. and Edin., 

&c. &c. . . . . 113 

II. An Account of Experiments to determine the Figure of the 
Earth by means of the Pendulum vibrating Seconds in different Lati- 
tudes ; and on various other Subjects of Philosophical Inquiry. By 
Captain Edward Sabine, F.R.S. &c. . • 141 

III. Remarks on Professor Spohn's Essay de Lingua et Literis 
Veterum iEgyptiorum, edited by Professor Seyffarth * 159 

XVI. Miscellaneous Intelligence. 
I. Mechanical Science. 
1. Dr. Black's Sensible Balance. 2. Tenacity of Iron, as ap- 
plicable to Chain Bridges. 3. Moving Rocks of Salisbury. 4. 
Etruscan Vases. 5. On the Repulsion exerted by heated Bodies at 
sensible Distances. 6. Polarized State of Halo Light. 7. Nature 
of Shooting Stars seen during Day-time. 8. Astronomical Prize 
Question ; Natural Philosophy 161 


CONTENTS. Ill 

PAGE 

II. Chemical Science. 

I. On the dry Voltaic Piles of M. Zamboni. 2. New Galvano- 
meter. 3. On the Length of the Electric Flash producing Light- 
ning. 4. On the Existence of Iodine in a Mineral Substance, 
5. Selenium in the Sulphur of the Lipari Islands. 6. Natural 
Sources of Carbonic Acid Gas. 7. Process for the Detection 
of Phosphate of Lime. 8. Metallic Titanium in Iron Furnaces. 
9. M. Rose on the Separation of Titanic Acid from Oxide 
of Iron. 10. M. Wohler on Tungsten, and its Combinations. 
11. Composition of Ancient Glass. 12. Action of Lime upon Al- 
cohol. 13. Melaina, or the Black Principle of Sepia. 14. Ana- 
lysis of the Solanum Pseudo-quina 159 

III. Natural History. 

1. Meteoric Appearance on Ben-Lomond; Ascent of Vapour. 
2. Description of an Earthquake. 3. Extraordinary Rise of the 
Rio de la Plata. 4. Fall of a Meteoric Stone at Nantgemory, Mary- 
land. 5. Composition of Aerolites. 6. Flexible Marble of Berk- 
shire County, U. S. 7. Extraordinary Minerals discovered at 
Warwick, Orange County, N. Y. 8. Globules of Water in Ame- 
thyst. 9. Recent Formation of Brown Hematitic Iron Ore. 10. On * 
the Habits of Beavers. 11. Tenacity of Life in Larvae. 12. Argo- 
nautaArgo. 13. Recent Vegetation of Ancient Beans. 14. On the I 
Origin of Ergot. 15. Action of Poisons upon the Vegetable King- 
dom. 16. On the Contents of the Digestive Canal in the Foetus of 
Vertebral Animals. 17. Remedy for Effects produced by Inhaled 
Chlorine. IS. Employment of Caustic to destroy the Variolous 
Eruption. 19. Preservation of Anatomicnl Preparations. 20. Phy- 
siological Prize Question. 21. Salt on the Shore of the Severn 1S2 

XVI. Meteorological Journal for June, July, and August . 202 


TO OUR READERS AND CORRESPONDENTS. 


A complete General Index to the first Twenty Volumes of this 
Journal is preparing for publication. 


An anonymous Communication from Portsmouth cannot be 
inserted. 

" A Chemical Student" will find the difficulty to which he 
alludes fully explained in our Review of Dr. Thomson's " At- 
tempW &c.' 

Communications have reached us from Dr. Wilson, Dr. Mac 
Culloch, Mr. H. Burns, Mr. Swainson, and Mr. Wells : these 
have of necessity been deferred. 

We are quite willing to listen to all reasonable suggestions 
respecting the improvement of this Journal, but the complaints 
of " a Mechanic" are without foundation .• we must remind him, 
that " ex nihilo, nihil fit." Had we blazoned forth, as did some 
of our contemporaries, either of* the schemes to which our friend 
alludes, we should have deservedly incurred the blame of hasti- 
ness and credulity. 

The reports alluded to by F. R. S. are false, as relating to 
the Royal Institution, and very far from correct as concerning 
the Royal Society : upon such grounds, we decline publishing his 
letter: to shew that no other feeling prevails, we shall be happy 
to insert it in our ensuing number, provided he will allow us to 
attach a commentary of our own. 

The review of a work inquired after by our correspondent at 
Warwick will probably appear in our January Number. 

We are apprehensive that the communication with which we 
have been favoured by " a Regular Reader" respecting the 
manufacture of chloride of lime, would not be intelligible with- 
out a drawing. 

Mr. Brande and Mr. Faraday mil commence the 
Lectures and Demonstrations in Chemistry in the Laboratory 
of the Royal Institution, on Tuesday Morning, the llth of 
October, at nine o'clock precisely. 

A Prospectus may be obtained at the Royal Institution. 
(See page 203.) 


CONTENTS 

OF THE 

QUARTERLY JOURNAL, 

No. XL. 


ART. PA GE 

I. On the Lignites. By J. Mac Culloch, M.D., F.R.S., &c. 
(Communicated by the Author.) 205 

II. Observations on the expressed Oil of the Seeds of Croton 
Tiglium. By John Frost, F.L.S., M.R.I., &c. (Commu- 
nicated by the Author.) , 231 

III. Outlines of Geology, being the Substance of a Course of Lec- 
tures on that Subject, delivered in the Amphitheatre of the 
Royal Institution of Great Britain. By William Thomas 
Brande, F.R.S., Professor of Chemistry in the Royal Insti- 
tution, &c 235 

IV. Experiments on the Action of Water upon Glass, with some 
Observations on its slow Decomposition. By Mr. T. Grif- 
fiths. (Communicated by the Author.) . . . 259 

V. Analyses of two Mineral Waters, from Springs in Windsor 
Great Park. By W. T. Brande, F.R.S., Professor of 
Chemistry in the Royal Institution . . . 264 

VI. On the Tyrant Shrikes of America. By William Swain- 
son, Esq., F.R. and L.S. (Communicated by the Author.) 267 

VII. Examination of the Large Achromatic of the Royal Observa- 
tory at Paris . , . 2S6* 

VIII. Observations on Mr. Fraunhofer's Memoir on the infe- 
riority of Reflecting Telescopes when compared with Refractors 2SS 

IX. Letter from M. Gav-Lussac to J. F. Daniell, Esq., F.R.S., 
M.R.I., &c., on the Expansion of Gases by Vapour . . 294 


808 
312 

315 
321 

ib. 


Vi CONTENTS. 

ART. PAGE 

X. Proceedings of the Royal Society . . . 296 

XI. Astronomical and Nautical Collections. No. XXIV, 

i. Continuation of the Catalogue of Comets, (Coll. No. XVI." 
By Dr. W. Olbers, Astr. Abh. iii. 

ii. Errors in the best Tables of Logarithms ; collected from vari 
ous Authorities ...... 

iii. Observations on Mr. Mendoza y Rios's Method of computing 
the True from the Apparent Lunar Distances. By Thomas Hen 
derson, Esq 

iv. Correct Formula for the Nutation. By Professor Bessel. Astr 
Nachr. 83 

v. Remarks on the Principles of Algebraical and Fluxional Nota 
tlon. By the Editor . . .... * 

vi. Occultations of the Planets and Fixed Stars not less than the 
fourth magnitude, visible at Greenwich in the year 1826. By Tho- 
mas Henderson, Esq. ...... 325 

XII. Analysis of Scientific Books. 

I. Philosophical Transactions of the Royal Society of London, for 

the year 1825. Part II. . . . .329 

II. Considerations on Volcanoes ; the probable Causes of their 
Phenomena, the Laws which determine their March, the Disposition 
of their Products, and their Connexion with the present State'of, 
and past History of, the Globe ; leading to the Establishment of a 
New Theory of the Earth. By G. Poulett Scrope, Esq., Sec. 
Geol. Soc., &c. . . . . . ,356 

XIII. Miscellaneous Intelligence. 

I. Mechanical Science. 
1. Effects of an Anti-Attrition Preparation. 2. Strength of 
Leaden Pipes. 3. Method of curing Smoky Chimneys. 4. Sug- 
gested Improvements in Light-houses. 5. Cuthbert's reflecting 
compound and single Microscope. 6. On the alteration in the bulk 
of successive portions of Air introduced into a Torricellian Tube. 

7. On the attraction manifested at sensible Distances by Solid Sur- 
faces moistened by, and immersed in, a Liquid, by M. P. S. Girard. 

8. On an unnoticed Mechanical Principle — explanation of the 
cutting of Steel by Iron. 9. Magnetic Rotation. 10. On the For- 
mation of a Society for the Cultivation of Naval Architecture . 375, 


CONTENTS. Vll 

II. Chemical Science. 

ART. PAGE 

1. Influence of Solar Light on the Process of Combustion. By 
Dr. T. M'Keever. 2. On the Simultaneous Action of Gaseous 
Oxygen and Alkalis on Organic substances. By M. Chevreul. 
3. Thorina, not a distinct Earth, 4. On the Distillation of fatty 
Bodies. By M. Dupuy. 5. Variation i n the Composition of the 
Atmosphere. 6. Action of Carbonic Acid on HyaroovJphurets. By 
M.Henry, jun. 7. Inspiration of Inflammable Gas. (Hydrogen?) 
By Signor Giacomo Cardone. 8. In a mixture of Muriate of , 
Potash and Muriate of Soda, to determine the proportions of each. 
9. On the Solution of Steel and Iron in Acids, and on the residua 
which remain. By M. Karsten. 10. Preservative against Rust. 
11. Combinations of Antimony with Chlorine and Sulphur. 12. On 
the Detection of Arsenic by Lime Water. 13. Artificial Gold, a 
new Alloy. 14. Simple Mode of obtaining Meconiate of Morphia. 
15. Rectification of Alcohol at common Temperatures. 16. Hygro- 
metric Property of Sulphuric Acid. 17. Simple method of exhibit- 
ing the Deflection of the Magnetic Needle by the Electric Current, 
18, Necessity of Water in the Preparation of Lead Plaster . 387 

III. Natural History. 

1 . On the Insalubrity of the Air of Marshes, in communication 
with the Sea. By M. Gaetano Giorgni. 2. Effects of Lightning 
on the Animal System. 3. Investigation of supposed Electric Cur- 
rents in the Nerves. 4. Relation of a Case of poisoning caused by 
the Honey of the Lecheguana Wasp. By M. Auguste de St. 
Hilaire. 5. Los3 of Memory. 6. On a peculiar Blue Matter ob- 
tained from certain Urines. By M. H. Braconnot. 7. Analysis of 
an Urinary Calculus from a Hog. By M. Wurzer. 8. Chinese 
Manner of forming Artificial Pearls. 9. Flying-fish in the Channel. 
10. Age of a Yew-tree. 11. Phosphate of Lime accompanying 
Iron Stone in Coal-beds, (Allier.j 12. Geology of the Severn. 
13. On the " Extraordinary Rise of the Rio de^la Plata," and on 
the Storms of that part of South America. 14. Remarkable Pheno- 
mena observed in the Island of Melida, Province of Ragusa. 
15. Edinburgh Prize Essay ..... 401 

XIV. Meteorological Table 420 

XV. Index 4-21 


TO OUR READERS AND: CORRESPONDENTS. 


The coals of the vicinity of Bath are very sulphureous — perhaps it is 
their vapour, and not their light which bleaches Arabella's dresses. The 
steam of 300° must be issuing- with arreat violence from a small aperture ; 
expansion then so mud* increases its capacity for heat that it does not 
scald till the r^ sSure is considerably diminished. Although the steam in 
the boiler may be 300°, that which first issues is not above 190°. 

Mr. W. Jones informs us that, in 1822, he proposed to Messrs. Symons 
and Co., of Leman-street, a plan precisely similar to Mr. Jeffrey's, for the 
condensation of smoke : we should be glad to know whether there, or else- 
where, it has been successfully carried into effect ? 

Captain Jeremie's observations on East India opium have been received, 
but the sample has not yet reached us. 

H. M. is informed that ice evaporates, as well as water. 

The hints of our Correspondent at Dover shall be attended to. He is 
surely wrong respecting our general index. 

In reply to a letter dated " Somerset, 22d September, 1825," we refer 
to what is called a Fossil Human Skeleton, preserved in the British 
Museum ; and to Mr. Konig's paper on the subject, published in the Phi- 
losophical Transactions. 

Mr. Van Rensselaer's communication has been received ; his former one 
never came to hand. 

We must again decline publishing the Letter of F.R.S., inasmuch as 
he reasons upon wrong grounds. The Library of the Royal Institution, 
as well as that of the Royal Society, are both easily accessible, and under 
certain restrictions, the Fellows of the Society arc allowed to take books 
from the latter. 

Several instruments have been invented for the destruction of calculi 
upon the principle of Colonel Martine's, but there are very few cases 
which admit of their use. 

Communications have been received from Dr. Johnson, Dr. Ure, Mr. 
Gregory, Mr. Stromeyer, Mr. Faraday, and Mr. Horner. 


A copious General Index to the Contents of the first 
Twenty Volumes of this Journal, which are now com- 
pleted, is ready for the Press, and will be delivered with 
the next Number. 


THE 

QUARTERLY JOURNAL 

October, 1825. 


Art. I.— On the Means by which Crabs throw off their 
Claws. By Dr. Mac Culloch. 

[In a Letter to the Editor.] 
Sir, 

It is well known that the tribe of crabs, using this popular 
term to comprise many genera of modern naturalists, have the 
power of parting with their claws by a voluntary effort ; and they 
are thus frequently taken, with one or more of these deficient, or 
of an inferior size to the rest, since they have also the power of re- 
producing them. As the nature of this singular process has never 
been described, and as it appears, at first sight, as it has always 
been conceived, a very unaccountable effect of voluntary or mus- 
cular power, I am induced to send you a sketch of the anatomy of 
the parts engaged ; with an explanation of the mode in which the 
animal appears to detach the limbs. 

This process appears to be effected by these animals whenever 
so serious an injury has been committed on any of the extreme 
phalanges as to render the claw useless ; no provision having been 
apparently made to repair any injury of those parts, although there 
has been one established for reproducing the whole limb. It is 
very easy to witness this effect when the animal is recently taken 
out of the water and in a vigorous state ; but a very short time is 
sufficient, in most species, to render the animal too feeble to per- 

Vol. XX. B 


2 Dr. Mac Culloch on the Means 

form that for which the utmost effort of its muscular powers ap- 
pears to be requisite. Being unwilling to propagate a method of 
adding to the torments of animals for the mere gratification of that 
cruel curiosity in which physiologists have too often, and with 
justice, been accused of indulging, I will not here communicate 
the method by which the animals, of this tribe may be induced to 
perform this voluntary mutilation ; but it is rather too well known 
to children who have been brought up on sea-shores. 

It is, nevertheless, doubtful whether the effort itself is attended 
with pain, whatever the previous torment may be, as it seems 
often to be done without any apparent motive. The whole tribe is 
of an extremely ferocious and irritable character ; and with many, 
particularly of the younger animals, the mere attempt to take 
them, even without actual contact, causes them to drop the two 
hands, or larger claws. Others do it if confined in a box or 
a glass of water ; and almost all of the smaller kinds, or half 
grown ones, part with any claw by which it is attempted to 
retain them. 

To render the description of this process intelligible, it will be 
necessary to understand the general structure of the limbs of this 
tribe. The accompanying sketch, (Fig. 1 , Plate I.) is from one gf the 
small claws of the spider crab, being the species just at this moment 
under my eye. The structure of the several parts, as well as the 
form of the limb, is of course somewhat peculiar to this species ; 
but the difference is not material among the whole, and the same 
explanation and drawing will, with slight modifications, apply to 
all the instances in which it occurs. Even if I had not acci- 
dentally had this species at hand, I should have preferred it ; as 
the structure of the suture where the separation takes place, is 
rather more distinct and remarkable than in the other species 
which I have examined. 

The limb of a crab consists of six parts, each of which has an 
appropriate motion in two directions, by means of a pair of muscles 
adapted to the nature and extent of the space to be described. In 
the extreme joint, the motion of direct flexion, towards the 'body, 
is considerable ; but the extension is limited by the structure of 


by which Crabs throw off their Claws. 3 

the shell ; and these motions are produced by two long muscles 
occupying the second phalanx. The motion of this phalanx upon 
the third, is lateral in two directions, and tolerably extensive, 
but less so than any of the direct motions. It is performed by a 
pair of muscles of considerable power, which lie in the third phalanx. 
The motion of this on the fourth, is a motion of extension and 
flexion, like that of the first ; the latter being, in the same manner, 
considerable, while the former is limited ; and the muscles that 
produce them are of considerable power, as occupying the great 
length of the fourth phalanx. 

The fifth phalanx is very short, and is articulated to the fourth 
in an oblique manner, by a very narrow ligament ; while the 
lower shell surmounts the upper one in such a manner as to limit 
the motion of the latter on the former to a very minute space 
laterally, which is also somewhat more considerable in one 
direction than another, but which varies, in this respect, in dif- 
ferent species of crabs. These lateral motions are produced by 
two broad, but very short, muscles ; as it will be shortly seen that 
but a small part of this fifth phalanx can be allowed for them, a 
great part of it being allotted to the arrangement provided for 
detaching the limb. 

The sixth, or last, phalanx, is extremely short, and is articulated 
by a somewhat lax ligament to the preceding, which admits also 
of a direct motion like those of the first and third ; but which is, 
on the contrary, much more free and extensive backwards than 
forwards. This phalanx is also connected with the former, by 
short and feeble muscles ; but the principal motions in this fifth 
phalanx, which are amongst the most powerful in the limb, are 
produced by two long muscles, a flexor and an extensor, which 
pass quite through the sixth phalanx, and are inserted within the 
body of the animal. The fifth phalanx therefore moves imme- 
diately on the body, independently of the sixth, or is, at least, 
capable of so doing. 

The last, or sixth phalanx, is connected with the body by a very 
wide ligament, admitting of a very considerable lateral motion, 
but more extensive inwards than outwards, and allowing the limbs 

Bt 


4 Dr. Mac Cullocli on the Means 

to be folded under the body. Some short muscles are appointed 
to this office ; but it is unnecessary to enter into further particu- 
lars ; as enough is given in this sketch of the motions of the limb 
and the position of the muscles, to illustrate the object of this 
paper. The beauty of the mechanism, by which strength of arti- 
culation is combined with extent and facility of motion, cannot 
fail to strike the most negligent observer of nature. 

It is in the fifth phalanx that the provision for detaching the 
limb is placed, and the accompanying sketches will assist in ren- 
dering the description intelligible. 

It will be perceived that, on the exterior side of this phalanx, 
there is a pale ring, transversely drawn round it (Plate I. Fig. 1.) ; 
and, with a magnifying glass, it is easy to perceive, though much 
more distinctly in some species than in others, that a very fine 
line lies in the middle of it, not exactly in one plane, but slightly 
undulated. (Plate II. Fig. 6.) If the edge of a knife be forced 
upon this line, it will be found that the phalanx, at the moment it 
yields, flies asunder with a loud crack. In every part of the shell, 
the bony matter is deposited in a fibrous manner, transversely to 
the plate ; but at this particular part, the fibres are peculiarly 
fine and straight, while the structure is also more brittle or 
tender and the colour paler, (Plate II. Fig. 8.) The division is, 
in fact, a natural suture ; nor is it possible to separate the joint 
in any other place than where this exists. 

If now a longitudinal section of the whole phalanx be formed, the 
appearance represented in Fig. 7 will be seen. It will be observed, 
that the suture occupies a thinner part of the shell, or that this 
portion is more slender than the general shell of the limb, and 
that it is bounded on each side by two reinforced rings. This is 
the case at least with the spider crab ; but it is less visible in 
some other species which I have examined, although the peculiar 
structure of the suture, in other respects, is always to be dis- 
tinguished. I must nevertheless remark, that in some, as in the 
lobster and crawfish, the external ring is by no means conspicu- 
ous, though the same provision exists in the internal arrangement, 
nor is it very obvious, externally, in the cancer pagurus. In the 


by ivhich Crabs throw off their Claws. 5 

same figure, there is a rude representation of the position and in- 
sertion of the muscles, as this is necessary for understanding the 
nature of the action by which the limb is detached. 

It will be seen that the two short muscles which produce the 
confined lateral motion between the fourth and fifth phalanges, or 
at A, (in Fig. 1, Plate I.) are inserted above the suture, (Plate II. 
Fig. 7,) and that the flexor, which alone is visible in this section, 
and which bends the joint at B, (Plate I. Fig. 1,) is attached below 
it ; the opposing extensor, not visible in this drawing, because 
occupying that part of the shell which has been removed, has a 
similar insertion. Thus there is left a vacant space between the 
two sets of insertions, on each side of the suture ; and this, 
according to the species or size of the animal, varies from a 
quarter to the eighth of an inch. In the living state of the animal, 
this is filled with a mucilaginous matter, which coagulates on 
boiling, so as somewhat to resemble the curd of milk; and which, 
after the voluntary separation of the limb, forms a protection to 
the ends of the last pair of flexors and extensors, and to the 
cavity of the joint. In Fig. 6, these muscles, by which the action 
of detaching the limb is produced, are represented as separated 
from their inferior insertions within the body ; bearing here the 
same proportion to the fifth phalanx, as they do in the species 
from which this drawing was made. 

It is now necessary to remark, that, in proceeding to detach the 
limb, the animal frequently throws the whole of the limbs into a 
state of violent extension, remaining perfectly rigid, as if under 
the operation of a tetanus or universal spasm. In other cases, 
the injured limb alone is so extended; and it is probable that 
these differences depend on the state of vigour or debility in the 
animal. When feeble, this action is often continued for some 
time, or relaxed, and again renewed, without producing the 
desired effect. But, when the animal is sufficiently powerful, the 
limb suddenly drops off at the suture, with a loud crack, in a 
second or two after the extension. 

This singular process seems, at first sight, to be capable of ex- 
planation, by considering the structure above described, and the 


6 Dr. Mac Culloch on the Means 

positions and actions of the last pair of flexor and extensor 
muscles ; and thus it has been attempted to explain it. It is 
obvious, however, on a moment's consideration, that no actions 
of these muscles, however powerful, could alone produce the 
consequence in question ; as they could have no further effect 
than that of fixing that part of the fifth phalanx, which is below 
the suture, more firmly on the body. To explain the mode in 
which their action is rendered efficient towards the separation of 
the limb, it is necessary to describe the forms and relations of the 
fifth and sixth phalanges more particularly ; as, in these, the true 
solution of the difficulty will be found. It is from inattention to 
these important circumstances, that this process has appeared so 
mysterious ; and assuredly it is difficult, on a first view of the 
operation as performed by the animal, to witness it, without sur- 
prise at the facility with which it is effected, and at the apparent 
inadequacy of any conceivable means for producing the separa- 
tion. The obvious effect of muscular action, is to approximate 
the insertions of the muscles ; yet here it appears to act as if it 
was to separate them. 

As it is impossible to render this structure intelligible without 
drawings, some sketches are added for that purpose ; and, as 
being more obvious in the common crab, (Cancer pagurus,) they 
are taken from that species. They are limited to the fourth, 
fifth, and sixth phalanges ; being the only ones required for 
illustrating the subject ; and these are numbered, so as to cor- 
respond to Fig. 1, Plate I. The place of the suture is indicated 
in these sketches, as it is not so defined externally as in the spider 
crab. In Plate II. Fig. 5, is an outside view of part of the limb in 
a state of flexion ; the state of extension being performed by the 
approximation of the points A, B, until they meet, so as that the 
indicating lines coincide in a common line C. In Fig. 2, Plate L 
the phalanx is in a half-extended state, and is further so turned, 
as to shew more distinctly the forms of the two phalanges at A 
and B ; while, in Fig. 3, Plate I. the extension being completed, 
the points A, B, are brought into absolute contact at C. Another 
view of the meeting of those points when in a state of extension, 


by which Crabs throw off their Claws. 7 

is seen in Fig. 4, where a front view of the limb is given ; and 
here also the coincidence of the two protuberances A, B, as the 
point of mutual contact, C, is indicated. 

In all the figures, the position of the suture is marked; and, in 
Figs. 2 and 3, an attempt is also made to shew the positions of the 
flexor and extensor muscles of this phalanx. These, passing 
through the last, or the sixth, phalanx, are inserted in the body of 
the shell below, and beneath the suture of the fifth phalanx 
above, and it is by them that the action of separation is effected. 
But the mode of action will be more easily understood, by simpli- 
fying the appearance of the parts ; as is attempted in that which 
is rather a diagram than a drawing, at Fig. 9, Plate II. In this, 
the shell is supposed transparent, to shew the directions and in- 
sertions of the separator muscles. 

The limb being firmly extended, the protuberance A is thus 
brought to rest firmly on B at the point C, and in such a 
manner, that the lower portion of the suture itself just touches 
the sixth phalanx. If the whole of the fifth phalanx, above the 
suture, could be thus supported on the sixth, it is evident that the 
contraction of the flexor and extensor muscles would draw the 
lower portion of the former towards the shell or body, the latter 
phalanx being at the same time pressed against it, and thus tend 
to separate the lower from the upper part of the fifth phalanx. 
But the necessary freedom of the motion of flexion would not 
admit of such a construction ; and the effect is therefore pro- 
duced in a different manner. 

For this purpose, the chief operation of the extensor muscle is, 
as before remarked, to fix the protuberance A firmly on B, which 
thus becomes a fulcrum, or point, on which the upper portion 
tends to revolve when the flexor is brought into action. Thus 
the flexor muscle acquires a lever of considerable power; and, 
on being caused to contract, it draws the lower portion of the 
fifth phalanx from the upper, and effects the separation. That 
this is the efficient cause, is rendered evident by the crack com- 
mencing at D ; although the whole is completed so instantane- 
ously, that it requires a quick eye to perceive a difference between 


8 Dr. Mac Culloch on the Means 

the commencement and the termination of the process. It is 
also easy to see that a collateral provision is made for this 
purpose ; as the suture is not only thinner but more feeble at this 
part ; being easily separated by insinuating a knife into it there, 
while it is scarcely possible to enter the point or edge at the 
opposite side. 

Those of your readers who may find a difficulty in comprehend- 
ing the nature of this process, from the preceding description, 
may easily satisfy themselves respecting it, by examining the 
structure of the parts, in an animal so common. This may be 
done, even after boiling ; when the structure and disposition of 
the muscles are, indeed, even more easily understood than in the 
living animal. But I may, I believe, add, that your London 
readers at least need not be surprised, if their trials of the 
powers of the living animals, in this respect, should fail ; as they 
are generally too much exhausted in that market, to enable them, 
to display this extraordinary faculty. 

EXPLANATION OF THE PLATES I. AND II. 

Plate I. Fig". I, is a whole leg- of the spider crab, intended to convey a 
general view of the articulations and motions of the legs of this tribe. 
The extreme, or first phalanx, has a direct motion forwards, but cannot be 
thrown backwards even into a straight line with the second, being checked 
by the form of the , articulation. These motions are effected by two 
muscles which occupy the entire length of the second phalanx. 

The second phalanx has no direct motions at all, but its lateral motions 
on each side are tolerably extensive, and are performed by two muscles 
similarly occupying the cavity of the third phalanx. 

The motion of the third phalanx on the fourth is direct ; but like the 
first articulation, this third one is so constructed, that the limb can scarcely 
be thrown back, even into a straight line. But the construction of the 
joint allows a very extensive motion forwards, and the connecting ligament 
is therefore lax and broad. The muscles of flexion and extension occupy 
the whole cavity of the fourth phalanx. 

The fourth articulation is very peculiar, the ligament being so narrow 
as to be scarcely visible ; and, in consequence of the form of the shell 
and the shortness of the muscles, the motion is very confined. It is lateral 


by which Crabs throw off their Claws, 9 

in either direction. The muscles, by which it is effected, are broad, but 
they arise from above the suture, or white ring, in the fifth phalanx, and 
are consequently very short. 

The fifth articulation, lying between the fifth and sixth phalanges, is 
very free, and admits of direct motion both ways. But it differs from all 
the preceding in the great extent of the motion backwards ; by which the 
whole limb admits of being thrown back, so as to be parallel to the flat 
surface of the animal. It has been already seen that this is the motion 
which prepares the limb for being detached, and the means by which 
this is effected will be more fully shown in the following figures. The 
ranscles by which the flexion and extension are performed, and which also 
by their action serve to separate the limb, are not, as in the former cases, 
inserted in the next, or sixth, phalanx, but pass quite through it, to be 
fixed in the shell of the thorax. Their origin is below the white ring, or 
suture, as that of the last pair was above it. 

The sixth and last phalanx is articulated to the body by a very wide 
and lax ligament, admitting, however, only of a lateral motion, which is 
performed by muscles inserted in its sides, and fixed at the other extremity 
to the shell of the body. 

Plate I. Fig. 2, represents the sixth and fifth phalanges, with part of 
the fourth, in a limb of the Cancer Pagurus. The place of the suture, in 
the fifth phalanx, is les3 marked in this species ; and it was for that reason 
that the spider crab was preferred, for the purpose of showing that part. 
It is, however, indicated in the figure. The limb is here thrown back by 
the action of the extensor ; and both the muscles are introduced, as sepa- 
rated from the body and passing through the sixth phalanx. The pro- 
tuberance of the fifth phalanx, which, in the act of detaching the limb, is 
brought to rest on the sixth at B, is shown at A. 

Plate I. Fig. 3, in this figure another view of the same parts is given, 
for the purpose of shewing the complete extension of the limb at the 
moment when it is to be detached. At the point C, the protuberance of 
the fifth phalanx at A bears strongly on the point B in the sixth, or A 
and B coincide at C. 

Plate I. Fig. 4, is a direct view of the interior of the limb at the same 
place, when in a state of extension. This figure is given principally to 
show the suture, which is very visible in the interior of the fifth phalanx ; 
while it also represents the bearing of the fifth and sixth on each other, on 
the opposite side at C. 

Plate II. Fig. 5. The same parts arc here represented in a state of 
moderate flexion, for the purpose of shewing more distinctly the protu- 


10 Dr. Mac Culloch on the Means 

beranecs of the fifth and sixth phalanges at A and B, which, in the act 
of extension, are to be brought into contact, or to coincide in a common 
line C. 

Plate II. Fig. 6, is the fifth phalanx, separated from all its con- 
nexions ; with its flexor and extensor muscles attached at one end, and 
the lateral muscles, by which it is connected with the fourth phalanx, 
shewn at the other. The suture is here distinctly seen. This is a joint 
of the spider crab. 

Plate II. Fig. 7, is a section of the same phalanx, for the purpose of 
shewing the suture distinctly, together with the insertions of the upper 
and under muscles. The ends of both those which lie between the fourth 
and fifth phalanx are shewn; but in consequence of that, only the flexor 
beneath is visible. It is here distinctly seen, that the shell is reinforced 
by a ring on each side of the suture ; and that it is not only thinner, but 
distinctly marked by a line indicating the future division between these. 

Plate II. Fig. 8, represents the dispositions of the fibres at the 
suture, after the division has taken place. They radiate from a common 
centre. 

Plate II. Fig. 9, is a kind of diagram, explanatory of the action by 
which the separation of the fifth phalanx at the suture is effected. The 
flexor and extensor muscles which produce the disunion of that part, are 
represented as if the phalanges were transparent, so that their whole 
.course is seen. The support or resistance which the sixth phalanx gives 
the fifth, by means of the meeting of the protuberances A and B at C, is 
also represented. When the limb is thrown into this position of extension 
by the action of the lower muscles, it is plain that the point C becomes a 
fulcrum, round which D may be caused to revolve. By means of the 
action of the extensor, the fifth phalanx is firmly fixed on the sixth, at a 
point above the suture, and somewhat beneath the upper insertion of that 
muscle. Thus its principal action becomes that of preserving this posi- 
tion ; as it has little or no tendency, from the shortness of the lever thus 
remaining, to bring back the limb into the state of flexion. Hence that 
action of the flexor, which would otherwise be exerted in retaining the 
bent position of the limb, is so counteracted that it tends to draw the 
phalanx asunder at the suture D, where provision is made for that 
purpose. It is plain that the action of the extensor tends also to produce 
the same effect ; the great resistance to that flexion, which would other- 
wise defeat this object, being that of the shoulders of the two phalanges 
atC. 

However obscure this subject may at first appear to an observer, from 


by which Crabs throw off their Claws, 1 1 

the obvious tendency of the muscles to bend the limb instead of break- 
ing- it, a careful consideration of these drawings, or of the limb of the 
animal itself with their assistance, will, it is hoped, render it perfectly 
intelligible. 


Art. II. — On the Fogs of the Polar Seas. By George 
Harvey, Esq., F.R.S., L. and E. 

[Communicated by the Author.] 

It has. been commonly supposed, that the fogs which cover the 
Arctic Seas during the greater part of the summer months, are 
produced by the moist air depositing its vapour, in consequence of 
being chilled by contact with the sea. But this cause, it is pre- 
sumed, is not adequate to the formation of mists ; since it has 
been proved by Dr. Wells*, that dew and hoar frost are the 
only results which arise from air, either perfectly or imperfectly 
saturated with moisture, coming in contact with a body colder 
than itself. To produce mist or fog, as has been satisfactorily 
demonstrated by Dr. James Huttont, it is necessary, that volumes 
of air, of unequal degrees of temperature, and holding moisture 
in solution, should be mingled together ; and the circumstances of 
the Arctic Seas, during the period when these fogs generally 
prevail, are, it is presumed, in perfect accordance with these 
conditions. 

Before the end of June, the shoals of ice are commonly divided 
and scattered ; the temperature of the ocean being at that time 
necessarily greater than that of the icy masses floating on its 
bosom. This inequality of temperature will necessarily impart a 
corresponding influence to the air, and occasion the portions of 
the atmosphere, resting on the broken surfaces of the water, to 
become warmer than the atmosphere in the vicinity of the ice* 
bergs. The cooling influence of the icy masses also, in conse- 
quence of their being elevated considerably above the sea, will be 

* Wells on Dew. 

t Transactions of the Royal Society of Edinburgh, Vol. I. 


12 Mr. George Harvey on the 

diffused, not only by radiations from their upper surfaces to the 
canopy of the sky above them ; but by horizontal radiations, to 
the air surrounding their sides. A volume of the atmosphere 
therefore, between two neighbouring masses of ice, will necessa- 
rily have its middle portion of a higher temperature than that of 
either of the portions of air between it and the icebergs * ; and 
the consequence of such an unequal distribution of temperature 
must be, to cause the cold air to mingle with that of a higher 
temperature, and thus to produce mist or fog. The density of 
such mist or fog will depend on the difference between the tem- 
peratures of the mingling volumes, and on the quantity of vapour 
contained in the air. 

The elevation of those mists above the surface of the sea will 
also be regulated by that of the icebergs, near which they form ; 
since the cooling influence of the frozen mass, by rapidly dimi- 
nishing above its summit, will as rapidly destroy all tendency in 
the portion of the atmosphere above the level of the iceberg, to 
assume a condition favourable to the formation of mist ; thus 
prescribing to the mist an elevation dependent on that of the 
iceberg near which it forms. Captain Ross accordingly remarks, 
in his Account of the Polar Voyage, " that the fog was extremely 
thick on the surface of the sea, but at the mast-head, and at the 
top of the iceberg, it was perfectly clear." Captain Scoresby 
also, in his Paper on the Fogs of the Polar Seas, read before the 
Wernerian Society t, alludes to their definite elevation, and to the 
sky above them being perfectly clear. 

It is possible, however, that two icebergs may be situated so 
near each other, that their reciprocal horizontal radiations will 
so cool the volume of air between them, as to reduce it to a tern- 

* If the water in the vicinity of icebergs presents considerable inequalities 
of temperature, the air which reposes on it must be subject to like variations; 
and numerous examples of the former are to be met with in the Accounts of 
the Polar Voyages. Thus Captain Franklin remarks, " the temperature of the 
surface water was 35° when among the ice, 38° when just clear of it, and 41°, 5 
at two miles distant." 

f Edinburgh Philosophical Journal, Vol. VI, 


Fogs of the Polar Seas. 13 

perature nearly uniform; and thereby prevent the formation of 
mist. The cold volume of air so formed, may, however, pass from 
between the icy masses, and by mingling with the air reposing on 
the warmer water, beyond the icebergs, produce mist at a distance 
from them. Nor is it absolutely necessary that two icebergs 
should exist, in order to form mist ; since the horizontal radia- 
tions of owe, by cooling the portion of air in contact with it, will 
cause it to mingle with the warmer air beyond the last-mentioned 
stratum, and thus create fog. The density of a mist when formed 
under the latter conditions, will be of a more variable character, 
than when it is formed between adjacent icebergs. 

The general diffusion of fogs over the Northern Seas may also 
be satisfactorily accounted for, from the scattered icebergs sepa- 
rating the water into detached portions ; and thereby creating, 
in innumerable directions, volumes of air, possessed of unequal 
temperatures. The cold air near the icebergs being blended, 
therefore, with the warmer air reposing on the middle portions 
of the broken intervals of water, must form, between most of the 
floating masses of ice, visible volumes of vapour, having their 
density dependent on the relative difference of heat between the 
mingling portions of air, and on the degree of humidity possessed 
by each. 

The cause here referred to, for the production of the Polar 
fogs, is also one likely to promote their continuance for a con- 
siderable time ; it being known, that the sea continues for many 
months relatively warmer than the icebergs ; and therefore 
capable, in conjunction with the constant radiation of the ice, of 
producing that almost constant succession of fogs which cover 
the Arctic Seas during the greater part of the summer months ; 
and which increase, in so considerable a degree, the difficulties of 
Polar navigation. 

Plymouth, July }9th t 1825. 


14 Dr. Hall on one of the Causes 

Art. III. — On One of the Causes of the Movements of the 
Barometer, and of the South and West Winds. By Mar- 
shall Hall, M.D., F.R.S.E., 8?c. 8?c. 

[Communicated by the Author.] 

Our inquiries into the nature and causes of the changes in the 
atmosphere will be greatly facilitated, by having first apprehended 
its more usual and quiescent state. The following observations 
will therefore be properly introduced by a very short description 
of what may be termed the natural state of the atmosphere. 

If the surface of the globe were even and uniform, unchequered 
by mountains and valleys, and unintersected by rivers and seas f 
the waters of which continually evaporate and recondense, the. 
atmosphere would remain in a comparatively tranquil state ; and 
those movements which did take place in it, being only excited 
by the influences of the sun and moon, would be regular and 
periodical, and would consist chiefly in a constant wind from the 
north-east in the northern hemisphere, and in a diurnal oscillation 
or atmospheric tide. This movement of the atmosphere from the 
north-east is produced in the following manner. The sun, acting 
powerfully on the surface of earth within the torrid zone, heats 
and rarefies the superincumbent air, and causes it to rise into the 
upper region of the atmosphere ; the place of this air is supplied 
from the poles, and thus, in the northern and southern latitudes, 
a north and south wind is produced respectively : as these portions 
of air have, however, little or no other motion except that in the 
direction towards the equator, and as the surface of the earth as 
we approach the equator has more and more motion from west to 
east, from its rotation on its axis, it follows that the air so 
brought from the poles, must, as it approaches the equator, have 
more and more of an apparent motion westward. These two 
motions being combined, the air will pursue the course of the 
diagonal, and to the inhabitants of the northern hemisphere of 
the globe, will constitute a perpetual north-east wind. 

Such is the principal effect of the sun's influence on our atmo- 
sphere. A further influence of this celestial body, and of the 


of the Movements of the Barometer, 8fc. 15 

moon, would be to produce atmospheric tides, similar to those 
observed in the sea, varying the weight of different columns of 
the atmosphere by augmenting and diminishing their height 
These tides would doubtless, too, be measured by our barometers. 
They are obscured, in the existing state of things, by causes 
modifying the elasticity of the lower region of our atmosphere, 
and so cutting off, for a time, the influence of the height and 
weight of the superincumbent columns. 

These regular movements of the atmosphere are disturbed 
chiefly by the irregularities on the earth's surface, by which the 
winds are diverted from their original and natural course, — being 
divided asunder by mountains, and made to clash violently together 
in the course of valleys and rivers. These effects are followed 
by others which arise out of the admixture of portions of air of 
different temperatures, and containing different portions of aqueous 
vapour; and it is not improbable that there are other phenomena 
of an electric nature, not hitherto fully appreciated and understood, 
which act silently and obscurely in general, though they are occa- 
sionally manifested in the phenomena of thunder and lightning. 

The object of this paper is not to treat fully of the movements 
of the Barometer, but to point out one of the causes of these 
movements more particularly than has hitherto been done. This 
cause is the transition of vapour in the atmosphere from the trans- 
parent to the opaque and fluid form, — or the formation of clouds, 
and of rain. We shall now, therefore, proceed to trace the effects 
of this change upon the elasticity of the atmosphere in the region 
of the clouds, and consequently upon the barometer. 

It is well known how much the presence of water adds to the 
expansibility of the air in contact with it, by heat. In the 
experiments of Guyton and Duvernois*, the object of which was 
to ascertain the comparative expansibilities of the different kinds 
of gas, the presence of an inappreciable quantity of moisture 
ioned an error of such magnitude, that, of gases which are 
now known to expand alike, some appeared to dilate five times as 
much as others by the same application of heat. 

* Journal de VEcole Poly technique, Cap. 2. + Enai sur C Hygrometrte. 


16 Dr. Hall on one of the Causes 

The rate of the expansibility of air in contact with water, is 
also greater as the temperature rises ; for, from the experiments 
of Saussuret, we learn that the power of air for retaining water 
in a transparent state increases in a geometric progression, whilst 
the temperature rises in an arithmetic progression only. 

From these considerations we are enabled to conceive how great 
the contraction of a given volume of atmosphere must be by the 
mere admixture of different portions of air charged with vapour 
and of different temperatures, even without the precipitation of 
water, but especially if, whilst its temperature is diminished, its 
transparent vapour be condensed and withdrawn, in the form of 
clouds and rain. 

To these considerations must be added, that of the vast extent 
of country over which the changes which take place in the at- 
mosphere are observed to diffuse themselves, — generally more 
than one thousand miles, — that of the extent and height of that 
region of the atmosphere occupied by the clouds — upwards of 
three miles, — and that of the immense quantity of water which 
must at some periods pass, in a very short space of time, from the 
state of transparent vapour to that of clouds or rain. 

If we fully consider the extent and magnitude of these pheno- 
mena, we must conceive that the degree of contraction in volume 
in that part of the atmosphere which constitutes the region of the 
clouds, must on some occasions be great indeed. Let us now 
consider what must be the further effects of this contraction in 
the immediate and adjacent region : — a portion of the atmosphere 
being condensed and withdrawn, the elasticity of the remaining 
portion occupying the same space must be diminished ; and, as 
further consequences, the barometer must fall, and the air of the 
adjacent regions must be attracted, and wind be produced ; — and 
these effects and phenomena will continue as long as the atmo- 
spheric process of the formation of clouds or rain continues. 
When the deposition of atmospheric moisture ceases, the equili- 
brium in the elasticity of the air is gradually restored, the 
"barometer rises to its natural level, and the wind or influx of air 
from the adjacent regions subsides. 


of the Movements of the Barometer, 1 7 

Hie fall of the barometer is thus connected, not with the exist* 
ence of clouds or the fall of rain, but with their formation. And 
we are enabled by this view of the subject to account at once for 
the undoubted connexion between the fall of the barometer and 
the fall of rain in general, and for a fact equally well established 
and frequently observed in the summer of 1823, that the baro- 
meter does frequently fall during fine weather and rise during 
rain, — the first phenomenon depending on the precipitation of 
water into the form of clouds, and the second on the circumstance 
of that precipitation having ceased; in this manner, when fair 
weather and rain succeed each other rapidly, the barometer may 
fall whilst clouds are forming, and rise when this process has 
ceased, though the rain fall. 

The connexion is not less obvious between the formation of 
clouds and rain and the fall of the barometer, and the occurrence 
of gales and of changes in the wind. 

It is probable, indeed, that these phenomena act and react in 
the atmosphere, and assume in turns the character of cause and 
of effect. The clash of winds is the cause of the first precipita- 
tion of moisture from the atmosphere, and the precipitation of 
moisture becomes, in its turn, a fresh cause of wind. 

That state of the baipmeter which is most generally observed, 
and which usually continues longest without change, may be con- 
sidered to be its most natural condition. This state approaches 
to its highest elevation, the barometer being far more frequently 
and for longer periods high than low, this state prevailing when 
no changes are going on in the atmosphere, and when the weather 
is of course calm and serene. 

The causes of the movements of the barometer are to be 
sought, therefore, not only in such phenomena as may be supposed 
to add to the weight of the atmosphere, but in such as may tempo- 
rarily diminish its elasticity, and concur with the disturbance of 
its transparency and tranquillity, or with the formation of clouds 
or rain, and of winds. 

To shew how much the low state of the barometer is connected 
with the formation of clouds or rain, I quote a remark from the 
Vol. XX. C 


18 Dr. Hall on one of the Causes 

Meteorological Observations of Mr. Dalton*. "Very dark and 
dense clouds," he observes, " pass over without rain when the 
barometer is high ; whereas when the barometer is low, it some- 
times rains without any appearance of clouds." 

The views just given are greatly supported by the observation 
that the variations in the barometer are confined to the lower 
region of the atmosphere, and diminish rapidly as we approach the 
upper limit of the region of the clouds. 

I now proceed to make a few observations on the influence of 
the condensation of atmospheric moisture as a cause of wind. 
The causes of the north-east wind have been already stated as 
given by various authors t. But I am not aware that any satis- 
factory cause has been assigned for the prevalence of winds from 
the south or from the west. It is plain, however, from the pre- 
ceding remarks, that such winds must be produced by great and 
rapid formations of clouds and rain, the air being drawn from all 
the adjacent regions to that in which this condensation of atmo- 
spheric vapour takes place, and thus under particular circum- 
stances a south-west wind or gale will be produced. 

Mr. Playfair has made some observations which appear to con- 
firm this view of the subject. He observes, " the sudden sinking 
of the barometer almost always indicates a gale of wind, though 
a gale that is sometimes at a considerable distance J." And 
further, " there is in our climate hardly any instance of rain 
without a change of wind, and very rarely a change of wind 
without rain in a greater or less quantity §." Mr. Dalton ob- 
serves, " the barometer generally rises with a wind between the 
north and east, and is very low in winter when a strong and 
warm S. or S.W. wind blows J." He adds, the lowest extreme of 
the barometer for five years, was accompanied with a strong S. 
or S.W. wind and and heavy rain, and occurred just after the 

* Page 196. 

t See La Place, Syst&me du Monde, t. 2. p. 174 ; Playfair's Outlines of 
Natural Philosophy, v, I. p. 293. 
X Outlines, v. I. p. 299. § Ibid. p. 305. 

f| Met. Obs. p. 118. 


of the Movements of the Barometer. 19 

highest extreme which took place during a long and uninterrupted 
frost. 

It is impossible to show more clearly than by these facts the 
connexion between rain, wind from the S. or S.W., and a low state 
of the barometer; I merely venture to suggest one mode of 
accounting for this association of phenomena : — during a period 
of atmospheric tranquillity, evaporation goes on from the surface 
of the earth, and expands and forms a part of the atmosphere, to 
the absolute weight of which it must necessarily add, and the 
barometer accordingly takes its highest station ; at length, from 
the collision of different winds induced by irregularities on the 
earth's surface, this vapour is precipitated, on the principle of the 
beautiful theory of Dr. Hutton*, viz. that, as the power of the air 
to imbibe moisture increases in a higher ratio than the tempera- 
ture, two portions of air of different temperatures, and saturated 
or nearly so with moisture, cannot be mingled together without 
its precipitation ; this precipitation is, in its turn, a fresh cause of 
wind, of the fresh collision of different airs, and of the renewed 
formation of clouds and rain, — and the contraction which thus 
takes place in the atmosphere diminishes its elasticity, lowers the 
barometer, and again becomes a cause of wind. 

According to this view of the subject, the barometer may be 
regarded as an instrument measuring the actual weight of a column 
of the atmosphere in serene weather, but in serene weather only. 
On other occasions it measures the changes which take place in 
the elasticity of the lower region of the atmosphere, the pressure 
of the superincumbent part of which is cut off for a time until the 
equilibrium be restored. From this view, too, we observe that it 
is only in serene weather, and with a transparent and tranquil 
atmosphere, that the barometer should be employed to measure 
the heights of mountains. That the variations of the barometer 
do, in fact, depend upon changes which occur in the lower regions 
of the atmosphere, is proved by the observations of M. Laval, re- 
corded in the Memoirs of the Royal Academy at Paris for 1709. 
During ten days the barometer was observed to vary two lines and 

* Trans, of the R.S. of Edin. v. I. p. 41. 
C2 


20 Dr. Hall on one of the Causes 

three-fourths at Marseilles, whilst it varied only one line and 
three-fourths at the top of St. Pilon, which is 960 yards above the 
level of the sea. 

; I must observe, in this place, that I am fully aware that it may 
be objected to the preceding observations, that the quantity of 
water in the atmosphere is not sufficient to account for the move- 
ments of the barometer, and for winds, from the changes in its 
state from transparent vapour to that of clouds or rain. To this 
objection I would reply, first, that it is the object of this paper to 
propose this, only as one cause of the movements of the barometer, 
and of wind, whilst it is admitted that there may be, and undoubt- 
edly are, many others ; and secondly, that the circumstances at- 
tending these changes in the state of the atmospheric moisture, 
and all the effects of these changes, are probably not yet fully 
understood and appreciated. Two points, at least, have been 
established : — the first, that there is an unequivocal connexion 
between the fall of the barometer, the production of wind, and the 
formation of clouds or rain ; the second, that the transition from 
the elastic to the fluid state of the atmospheric moisture does, in 
part y at least, account for these phenomena — must be attended by 
a certain diminution of bulk and elasticity — and consequently by a 
movement in the adjacent regions of the atmosphere, and by a fall 
in the barometer. The principles here pointed out may obtain in 
the minor but more usual changes in the atmosphere ; whilst the 
more extraordinary phenomena of gales and tempests may, and 
doubtless do, involve many other. Our atmosphere is so compli- 
cated a structure, that no simple theory will ever explain the 
whole of its phenomena. It has just been suggested, that as all 
the causes of the movements of the barometer are not hitherto 
ascertained, so all the circumstances attending the precipitation 
of the atmospheric vapour, assumed as one of these causes, are 
probably not yet fully appreciated: — one effect of the condensa- 
tion of the atmospheric moisture, is an actual diminution of the 
weight of the atmosphere, and this would operate on the baro- 
meter, were the elasticity of the air unaffected ; but as the vapour 
really constitutes a part of the atmosphere, and adds to its volume, 


of the Movements of the Barometer. 21 

its subtraction or precipitation must also diminish the elasticity of 
the remaining portion of the air, and, in this manner especially, 
lower the barometer ; and this effect will be the greater in conse- 
quence of the atmospheric vapour being accumulated, and its 
precipitation chiefly effected, in the lower region of the atmo- 
sphere, in which the movements of the barometer are consequently 
observed to be proportionately greater than in more elevated 
situations. 

In conclusion, I would observe, that as I should probably never 
have taken the pains with this subject which I have done, but 
with the view of laying it before our little Society, so my wishes 
will be fully attained if this paper either excite interest or afford 
instruction even to the youngest of our members, and thus tend to 
further the object of our meeting together. My great aim, indeed, 
has been to allure and aid the beginner in philosophical studies ; 
and such, I imagine, to be the specific design of our institution. 
With this view conjectures and observations which might otherwise 
never have deserved attention become extremely valuable. — If any 
further apology were required for the preceding pages, I would 
say that the current of my studies has of late years flowed in a 
totally different channel from that of philosophy ; but that it was 
only by recurring to the studies of former days that I could select 
any subject which would be appropriate to the present occasion. 


Art. IV. Description of an Instrument for destroying 
Stone in the Bladder. By J. R. Griffiths, Esq, 

[Communicated by the Author.] 

I had long entertained the idea that an instrument might be con- 
structed, by means of which a calculus in the bladder could be 
broken down into fragments small enough to pass by the urethra, 
and about three years since, with the assistance of an instrument- 
maker, I attempted to put my plan in execution ; but not at that 
time being able to construct a drill that would work in a curve, I 
gave up the attempt. Some time after this I heard that an inr 


22 Mr. Griffiths' Description of an Instrument 

strument for the same purpose had been invented, and used with 
success in France, and which was somewhat on the same principle, 
excepting that it had no curve, it having been found that a 
straight instrument might be passed into the bladder of many 
persons. 

Notwithstanding what was said of the success of this con- 
trivance, I conceived it would be very desirable to form one 
which would be better adapted to the natural curve of the urethra, 
and with which there would be less danger of injury to the blad- 
der in attempting to seize the Stone. Under this impression I 
determined to make another attempt, and for this purpose I ap- 
plied to Mr. Ferguson, a very ingenious Surgeon's Instrument 
maker, in Castle-Street, Leicester Square ; he entered fully into 
my plan, and was of very great assistance in carrying it into exe- 
cution, and completing the instrument hereafter described. 

The instrument (Plate III. Fig. 1.) for the sake of convenience, 
is represented somewhat smaller than the original model ; it con- 
sists, in the first place, of a tube twelve inches long, A A re- 
sembling a catheter, with the exception of its being open at both 
ends ; B is an arm coming off, which connects the whole together, 
and at the same time serves for a handle. Fig. 2, is a stilet^ with 
a knob at the end, which fills up the opening at the extremity of 
the canula, so as to enable it to be passed into the bladder without 
injury to the urethra, after which it is to be withdrawn, and the 
apparatus for seizing the stone is then to be introduced ; it con- 
sists of a tube six inches longer, and about the eighth of an inch 
less in diameter than the first, the anterior part of which is made 
flexible, to enable it to take the curve of the canula, in the same 
manner as the old elastic catheters were constructed, which is by 
means of winding up a narrow strip of silver into a spiral form; 
part of this is seen at D, the anterior extremity, which, in Fig. 1, 
is concealed in the canula, and is represented at F F, Fig. 3. The 
surface of this tube is divided by ridges into four compartments, 
which at the same time keep it steady* and allow space for the two 
narrow watch springs G G, to pass between the two tubes, and 
prevent their catching in each other ; at the extremity is a collar 


for Destroying a Stone in the Bladder, 23 

E, Fig. 3y which exactly fills up the interval between the tubes, 
and in which there are four holes for the passage of the springs, 
which have a small bit at one end turned down to prevent their 
being drawn through, and the temper of the steel is lowered, so as 
to admit of their being freely bent : they are passed from within 
outwards through two of the knobs, and brought back by the 
others, so as to form two loops, with which it is proposed to fix the 
stone ; they cross each other and pass through a ring H, which 
rises and falls as you increase or diminish the bow of the springs. 
The other ends pass down in the grooves before-mentioned, and 
are fixed in the collar I. Fig. 1, by the screws K K, and by means 
of which they are slid up and down, either together or separately ; 
L is a screw which fixes the collar when the stone is caught by the 
loops ; m m is an elastic wire wound round the part of the inner tube, 
which is not enclosed in the canula, and serves to prevent the 
springs from bending outwards when pushed up ; N N is a drill ; 
the part of which that works in the curve is constructed in the 
same manner as the flexible part of the inner tube, but the metal 
is thicker, to give strength to bear the pressure necessary to per- 
forate a stone ; the other end is made of pinion wire, which passes 
through corresponding grooves in the pulley O, which enables it 
to be pushed forward at the same time that it is turned ; the ex- 
tremity works like a swivel in the socket P, attached to the ring 
R. The drill head takes off, that different sked ones may be 
used ; they are made to cut one way only, as the flexible part, 
though quite firm enough when turned in one direction, in the op- 
posite would have a tendency to unwind, if.it met with much re- 
sistance. 

To make use of this instrument, the canula, with the stilet in 
it, is passed ; the latter is then withdrawn, and the second tube, 
with the watch springs attached, is pushed through it, and the 
end fixed in a hole in the upright S ; the collar is then slid up, 
and the springs bow out in the manner represented in the plate : 
the springs may be worked up and down till the calculus is 
caught ; it is then fixed by means of the screw in the collar, and 
in this way can be retained more firmly than with any forceps ; by 


24 Mr. Griffiths' Description, Sec. 

having the springs of sufficient length, a very large loop may be 
made, and I should think without any fear of injuring the bladder : 
if the calculus should be small, it may be drawn out through the 
canula; if too large for that, it must have holes repeatedly 
drilled, till it crumbles into pieces small enough. 

The principal advantages that this appears to possess over the 
French instrument before alluded to, are, 

1st. Its form is better adapted to the urethra. 

2nd. It can be made of a smaller size. 

3rd. There is less chance of hurting the bladder with the bent 
springs, than with the forceps. The loops will fix the stone more 
securely, and if either of them should happen to be broken, both 
the parts can be withdrawn through the canula, and a fresh spring 
immediately adapted to it. 

4th. The fragments, or small calculi, will pass off by the 
canula, without injury to the urethra ; this may be assisted by in- 
jecting water, and letting it out again in a full stream. 

To destroy a calculus of any size would require the instrument 
to be used a great number of times ; but however tedious, many 
persons, I think, would prefer it to the dangerous operation of 
lithotomy, and would resort to it at an earlier period of the^ dis- 
ease, when the stone had not acquired much bulk, and the symp- 
toms were not so urgent as to make immediate relief necessary. 

Bentinck-Street, August, 1825. 

Art. V. — Outlines of Geology, being the Substance of a 
Course of Lectures on that Subject, delivered in the Am- 
phitheatre of the Royal Institution of Great Britain, by 
William Thomas Brande, F.R.S., Professor of Chemis- 
try in the Royal Institution, fyc. 

[Continued from Vol. XIX., page 198.] 

IV. 

There are abundant difficulties in the way of any satisfactory 
theory respecting the origin of the diluvial remains of quadrupeds, 


Outlines of Geology. 25 

&c, which were adverted to in the last lecture. If we consider 
them as having lived and died in the caves, and on the spots 
where their remains now occur, we must presume, either that 
their habits and propensities were extremely different from those 
of the now existent species of the same tribes ; or, what is yet less 
admissible, that the temperature of the northern regions was 
formerly correspondent with that of equatorial climates. Again, 
if we imagine the bones to have been transported thither by 
water-carriage, at the time of the deluge, how, it will be asked, 
can they have escaped attrition? — and not this only, for they 
actually retain in perfection all the tuberosities and processes 
which enable the anatomist to recognise them. To get over this 
latter difficulty, it has been conceived that the bones were not 
transported along with the pebbles and gravel, but that they 
came safely packed and protected in their including carcasses, 
floating upon the surface of the waters, and were afterwards 
deposited safely upon the mud or gravel, where the flesh rotted 
and decomposed, and the bones remained uninjured. We know 
how readily this kind of transportation takes place, how rapid 
the carriage may be, and supposing the temperature not very 
high, we also know that many weeks might elapse before the 
carcass would sink. I shall not at present venture to give any 
opinion upon this question, but shall refer my audience to the 
works of Professor Buckland, as the advocate of the one hypo- 
thesis, and to those of Mr. Granville Penn, who has defended 
the other. 

We may now proceed with our description of the strata, upon 
which the former materials are deposited : these are the super- 
medial rocks of Phillips and Conybeare, and include the varieties 
of chalk, green and ferruginous sands, oolite or freestone, lias, 
and red marie or new red sandstone. 

Below the varieties of clay, the position and contents of which 
formed the subject of the last lecture, we find the chalk which has 
already been stated to constitute the cavities of basins, in which 
the various alluvial matters are deposited. The ranges of chalk 
hills in the south of England are very extensive, and the land* 


26 Outlines of Geology. 

scape which they constitute, peculiar for the smooth and rounded 
outline of its hills, their monotony of surface, and for the singular 
cup-shaped concavities and deep hollows in which their sides 
abound. The situation and extent of the chalk in England is 
best shown by reference to coloured geological maps. Salis- 
bury Plain and Marlborough Downs form a centre, as it were, 
from which the chalk emanates in a north-east direction, through 
Buckingham, Bedford, and Cambridgeshires, and terminates on 
the coast of Norfolk in one direction. Another branch, inter- 
rupted by the Valley of the Humber, traverses Lincolnshire, 
terminating at Flamborough Head in Yorkshire. 

The extreme western point of the chalk is not far from Honiton 
in Devonshire, whence it branches off toward the south-east to 
the Isle of Purbeck, and again appears, forming a ridge that 
crosses the Isle of Wight. Near Hungerford, in Berkshire, 
another range of chalk commences, and passes by Alton and 
Rochester to the coast of Kent, forming the cliffs between 
Folkstone and Deal. From near Alton, another branch passes 
off, and ends at the lofty promontory of Beachy Head on the 
Sussex coast. In this chalk district there are some considerable 
elevations. Near Dunstable and Shaftesbury, for instance, it 
forms hills nearly 1000 feet above the level of the sea. Between 
Lewes in Sussex, and Alton in Hampshire, there are several 
similar elevations. Between Alton and Dover, the highest point 
is about S00 feet, and the Castle Hill is about 470 feet high. The 
chalk cliffs near Folkstone, and those near Lyme in Dorsetshire, 
are between 5 and 600 feet high. 

Chalk, like the strata that lie upon it, abounds in organic 
remains, but they are of a different and more ancient character, 
exhibiting many new genera, and scarcely a single species quite 
identical with any that now exist. They are chiefly as follow : — 
Remains of vertebral fish, such as teeth of a species of 
shark. 

Among the testaceous mollusca, are ammonites and belemnites, 
generally in the lower strata only ; a few spiral univalves and 
several bivalves. 


Outlines of Geology. 27 

Echini are very characteristic of chalk, and among them many 
species, and one genus, are peculiar to it. It also includes star 
fish, encrini, many madrepores, alcyonia, and sponges. 

The forms of sponges and of the alcyonia and echini, are not 
uncommon in the flints ; also casts of ammonites, and of nautili. 
These remains are not equally abundant in all parts of the chalk 
strata, nor are the strata themselves in all places similar. The 
upper beds of chalk abound in flints, which are usually disposed 
in regular horizontal layers, though there are cases in which, 
from some derangement that appears to have occurred to the 
strata, the flints are nearly vertically arranged, as in the Isle of 
Wight, and on the Dorsetshire coast. But, not the least remark- 
able fact, in respect to the perpendicular flints is, that they are 
generally splintery and broken, while those which are horizontal 
are in the usual state of rounded nodules. As the opposite coast 
of Dorsetshire exhibits a very similar arrangement, it is ex- 
tremely probable that this chalk ridge has once been con- 
tinuous, and that the shock or catastrophe that has broken 
it down, has also caused those inclinations, and that verti- 
cally of the strata once horizontal, that I have just adverted 
to. In the lower chalk strata, the flints become less abun- 
dant, and it frequently has a gray colour, and is argillaceous. 
These strata may be seen near Ryde in the Isle of Wight, and 
at Guildford and Dorking in Surrey, and the lime which such 
chalk affords derives certain peculiarities, as far as its use in 
making mortar is concerned, hi consequence of its aluminous 
character. The greater part of the chalk hills in Cambridgeshire 
are also composed of the lower or gray chalk, and they gradually 
pass into a kind of gray clay called gault, and into several 
varieties of argillaceous loam. In the neighbourhood of Deal, 
and in some parts of the Isle of Wight, the flint assumes the 
appearance of flattened or tabular masses, which are sometimes 
lost in a very thin edge. Near Freshwater in the Isle of Wight, 
these tabular flints are arranged in diagonal layers, crossing 
each other in opposite directions. 
v Although the flinty chalk is not always found upon that without 


28 Outlines of Geology, 

flint, it appears likely, from an examination of the neighbouring 
soils, that it has, at one time or other, everywhere existed ; 
indeed the enormous quantity of alluvial flints, and the deposits 
of rounded masses and nodules of chalk, which fill up the hollows 
in many parts of the chalk strata, are abundant indications of the 
destruction to which the chalk has been exposed. A degradation 
to which its exterior situation and its softness render it peculi- 
arly liable. 

The cliffs at, and about Brighton, are particularly remarkable 
for the changes and devastations which they record. The town 
stands upon a bed of fragmented calcareous matter and flints, 
which, on the east, is seen resting upon shingles, consisting chiefly 
of flints, but mixed with rounded masses of granite, slate, and 
porphyry, cemented together by crystallized carbonate of lime, 
apparently derived from the solvent action of water upon the 
superincumbent chalk, thus forming a hard and durable breccia. 
Nodules of pyrites, and of crystalline carbonate of lime, are not 
uncommon in chalk. They are of a radiated texture, and the 
latter often unusually hard. 

Having stated thus much respecting the composition and con- 
tents of the chalk strata, I have little or nothing to add, relative 
to their origin and that of their included fossils. The nature and 
characters of chalk seem to announce it as an aqueous deposit; 
but we must not be so bold as some geologists, who conclude that 
it is the detritus of coral reefs, and the dust of shells originally 
derived from the antediluvian ocean. The existence of various 
organic remains announce the existence of those animals at the 
time of its deposit, but we never find in it the bones of quadru- 
peds, or of animals of existing species ; and this circumstance 
appears to declare it of a date anterior to that of those superincum- 
bent beds, which we examined at our last meeting. The origin of 
flints, their arrangement, the peculiarities which they occasionally 
exhibit, and the fossils they occasionally include, are subjects 
that entirely baffle all theory, and it would be mere waste of time 
to recite the hypotheses they have given rise to. Like the chalk, 
however, they bear marks of aqueous, rather than of igneous 


Outlines of Geology. 29 

origin ; they contain the same fossils, echini, sponges, and other 
substances found in the chalk; and what is curious, many of 
them are hollow, and contain powdered siliceous earth, provided 
they have no perforations ; but if hollow and perforated, they are 
filled with chalk. 

The next beds that occur, in order of succession to the chalk, 
are several varieties of sand and clay ; the former is often called 
green sand, from the fragments and particles of chlorite and 
green earth that it contains, and it is sometimes so compact and 
hard, as to be fit for a building material of no trivial durability. 
To what extent this formation accompanies the chalk is not quite 
obvious, but it occurs in many places on the western side of the 
chalk range extending from Dorsetshire into Yorkshire, and also 
upon the coasts of Dorset, Kent, and the Isle of Wight. This sub- 
stance generally effervesces with acids, from the calcareous matter 
that it contains, and is abundant in organic remains ; more especi- 
ally those of the alcyonium, supposed to be a species of zoophite, 
and seen in a very characteristic manner at the back of the Isle of 
Wight, where large masses of this rock are lying upon the beach,- 
having fallen in consequence of the washing away of the marly 
strata upon which they repose. This marie is of a bluish-black 
colour — in the Vale of Aylesbury in Bucks, and in that of the 
White Horse in Wilts, this stratum forms a tenacious clayey soil— 
and at Shotover Hill, Oxford, it abounds in oyster-shells, selenite, 
pyrites, and other fossils. Mr. Webster has particularly made 
us acquainted with the characters and peculiarities of this sub- 
stance in the Isle of Wight. The sandstone strata that form the 
perpendicular rocks at the under cliff, lie upon a stratum of blue 
marie, which being soft and yielding, is occasionally washed 
away by land springs ; the superincumbent rock of course falls, 
and to this cause we may attribute that ruined appearance which 
is so characteristic of the back of the island, and which variegated 
with woods and corn fields, gives a peculiar and highly picturesque 
character to that delightful spot. At Black Gang Chine, the 
washing away of the blue marie by the waters that filter from 
the higher land, and through the over-lying strata, is particu- 


30 Outlines of Geology, 

larly well marked, and hence the cause of those land slips as they 
have been called, one of which took place to a great extent in 
1799, and another about ten years ago. 

The clays, gray chalk, and marles, which are common in many 
parts of the country that bound the chalk hills, scarcely admit of 
distinction into strata ; they are often more or less intimately 
mixed with green sand and contain beds, masses, and nodules of 
sandstone and limestone ; these all appertain to the formation we 
are now speaking of, and lie upon those very extensive beds of 
sand, commonly called ferruginous or iron sand, of the characters 
and situation of which it will now be right to treat more 
at large. 

This stratum must be distinguished from the sand lying above 
chalk, as that of Blackheath and of Bagshot. It is much more 
extensive, and constitutes a leading feature of many of those 
countries which contain or border upon chalk hills. It is 
accompanied and often blended with some varieties of lime- 
stone, and frequently it scarcely is to be regarded as a distinct 
formation from green sand — perhaps its best character, its most 
marked and leading feature, is the quantity of oxide of iron that 
it occasionally contains, and which is so considerable in ^ome 
parts of Kent and Sussex, as to have been formerly employed as a 
productive ore of iron. These ferruginous masses and veins are 
very abundant in and about Crowborough Heath, and the extensive 
district comprehended in a triangle, of which Dover, Beachy Head, 
and Alton, form the points, is chiefly composed of this kind of 
sandstone — here and there intermingled with other beds, but 
seen in characteristic masses on the coast near Hastings. Leith 
Hill, in Surrey, is also a good specimen of this formation ; it rises 
to nearly 1000 feet above the level of the sea: at Bottom 
Head on the coast of Yorkshire, it forms an elevation of nearly 
1800 feet, which is perhaps the greatest height which it attains in 
England. This sandstone is seen with most of its peculiarities in 
the neighbourhood of Tunbridge Wells, and although in many 
places it is almost barren, or only covered with furze and heath, in 
others, where it contains embedded or intermixed clay and lime- 


Outlines of Geology* 31 

stone, it constitutes a soil not unpropitious to the growth of 
several forest trees, and even bears very stately oaks. Near 
Woburn, in Bedfordshire, this sand is largely planted with firs ; 
and there, as well as at Ryegate, in Surrey, it contains large beds 
of fuller's earth. The organic remains which it contains in 
greatest abundance are nautili and cornua ammonis. This for- 
mation may be traced with little interruption from the neighbour- 
hood of Shaftesbury in Dorsetshire, to St. Neots, in Huntingdon* 
shire. It appears again on the east coast of Norfolk ; reappears 
at Spilsby in Lincolnshire, and again in Yorkshire, where it 
reaches the north coast of that county, and covers much of its 
western district. In many places this sand is associated with 
and overlies several varieties of clay of different texture and 
and composition, and often assuming a slaty aspect, and contain- 
ing bituminous substances, pyrites, and in some places, as about 
Whitby in Yorkshire, a considerable quantity of sulphate of 
alumina. On the south coast of England, as, for instance, in the 
Isle of Purbeck, this shale is abundantly bituminous, and forms 
what is called Kimmeridge coal. Organic remains are not rare 
in it ; and in Wiltshire, it is associated with several varieties of 
limestone, in which they are extremely abundant. It is, however, 
doubtful, whether these substances should not rather be referred 
to the oolite formation, which is extremely extensive, and which 
is seen in the map proceeding from Somersetshire to the banks 
of the Humber in Lincolnshire. Carbonate of lime is its leading 
ingredient, and several of its varieties are used as building mate- 
rials, such as Bath, Purbeck, and Portland Stone. Its texture, 
however, is such, that it is generally easily acted upon by the 
weather, and it is difficult to suggest any good criterion by which 
its relative durability may be judged of. It is sometimes sup- 
posed, that a comparative estimate of its value and permanency 
may be founded upon its absorbent powers, in regard to water, 
but this is not always strictly true ; that which abounds in shells 
and other organic remains is generally very subject to decay. 

In the quarries in the isle of Portland, three distinct strata are 
visible j the uppermost called by the quarrymen the cap, consists 


,32 Outlines of Geology, 

of fragmented and decomposing masses ; it is immediately suc- 
ceeded by horizontal seams, containing chert, flints, and some 
fine specimens of petrified wood ; below it is the useful Portland 
stone. In this island, the beds dip to the south, and alternate 
with strata of bituminous shale. The limestones belonging to the 
oolite formation, are of various degrees of granular fineness, and 
when made up of an agglutination of small rounded concretions, 
they are particularly called roestone. 

In contact with the lower beds of the oolite, we find more com- 
pact limestone or lias, which may be considered as the lowest 
member of this formation ; its different layers present various 
shades of white, gray, and blue, and it is generally speaking 
so argillaceous, as to exhale a strong earthy odour when breathed 
upon. To this ingredient, and to a portion of oxide of iron, the 
peculiarities of lime from this lias are referrible. It accompanies 
the great oolite formation, and is . seen extending from Ilchester 
in Somersetshire, by Bath and Gloster across the centre of the 
kingdom, terminating near Lincoln. A little to the north of 
Gloster, it forms eminences of more than 1000 feet high. These 
strata enclose a great variety of sea-shells, ammonites ; and at 
Lyme, on the Dorset coast, they contain the skeletons and de- 
tached bones of a large animal, which has generally been re- 
garded as the crocodile, but which Sir Everard Home has shown 
not to be that animal, but a peculiar extinct species, which from 
an analogy that exists between its spine and that of the Proteus, 
he has called Proteorachius. As these strata contain such re- 
mains of amphibious animals, they make it probable, in the opi- 
nions of certain geologists, that fresh water and dry land existed 
previous to the formation or deposition of the oolitic strata, and 
consequently, of course, anterior to the chalk hills and their vari- 
ous superincumbent substances. 


V. 

We have now cleared our way to the great red sandstone for- 
mation, or to the red marie of modern geologists,— a substance 


Outlines of Geology.' 33 

of very extensive occurrence, and involving the history ol Some 
important deposits, more especially, that of coal. I shall not 
stop here to explain the differences of opinion respecting the 
Wernerian phraseology applied to this rock, but it will be found 
that a very analogous substance occurs at greater depths, or 
among older rocks, and is. then emphatically termed old led sand- 
stone ; the terms, new red sandstone, red marl, or the mere pro- 
vincial phrase red ground being applied to that formation which 
follows the oolite, and which we may now proceed to examine. • 

In the first place, in regard to situation, the red marl extends, 
without material interruption, from the east of Somersetshire to the 
northern bank of the Tees in Durham. The map shows the occur- 
rence of coal, beds in this district, the great coal formations, or coal 
basins as they are often called, being apparently deposited in the 
inferior or mountain limestone, and covered by, and alternating 
with red marl, or some of the substances with which it is directly 
associated. It may not be irrelevant to take a general view of the 
positions of this rock in the several coal counties, and to notice 
the other substances which form its constant or occasional ac- 
companiments; and in doing this shall I make use of Mr. Phillips's 
abstract of the papers in the Geological Transactions i elating to 
this formation. 

Red sandstone generally forms a flat and low countiy, or where 
elevated into hills, their slopes are gentle, and their outline 
rounded. In the midland counties, it is traversed for a con- 
siderable length by the Severn ; and the Ouse and Trent, streams 
tributary to the Humber, take a long course through its plains. in 
the north. In the south-east part of Durham it exhibits strata 
of various colours, containing coal and gypsum. In Westmoreland 
it covers a considerable plain on the west of the range of moun- 
tains, of which Crossfell is the highest, and which is near the 
south-western extremity of the great Newcastle coal-field. The 
southern parts of Lancashire, the north of Shropshire, and the 
whole of the intervening county of Cheshire, are principally cha- 
racterized by their plains of red marl, and in Worcestershire it is 
also a prevailing rock, as also in various parts of Derbyshire, 

Vol. XX. D 


34- Outlines of Geology. 

Nottinghamshire, ami Staffordshire. Without, however, further 
enumeration of tho situations in which this rock occurs, a glance 
at the map will show its extent, and we may employ our remaining 
time by shortly advsi ting to its contents and embowelled treasures. 

The texture of led sandstone, and I had almost said its colour , 
.are very various; sometimes it is very soft and clayey, but in 
parts much more lapideous and indurated, and it is associated with 
beds of a peculiar conglomerate, consisting of nodules of different 
substances, cemented by marl or sand, and with a rock which we 
shall afterwards describe under the name of amygdaloid. It is 
generally unfit for aichitectural purposes, and from its softness 
has been in some places extensively excavated, as near Notting- 
ham, where it is suspected that these caves may have formed the 
dwellings of the aboriginal Britons. 

Deposits of gypsum, or sulphate of lime, are very characteristic 
of red marl, and this is a substance of no small importance as an 
article of trade ; the larger masses are occasionally manufactured 
either in the turning lathe or by hand into vases and various 
ornaments, and are sometimes used in decorative architecture, of 
which the columns in the hall of Keddlestone House in Derbyshire 
are fine specimens. The coarser varieties are employed in the 
potteries for making moulds, and some of the finer fibrous varie- 
ties are cut into beads and broach stones of no mean beauty. 
When heated, it loses water, and crumbles into a white powder, 
well known as plaster of Paris, and employed for casts and a 
variety of ornamental work. It has also been tried as a manure, 
but not with much success in this country, nor has any light been 
thrown upon the manner in which it operates as such. Sulphate 
of baryta, and sulphate of strontia, have also been found in this 
formation, but no organic remains have ever been discovered in it, 
although theie are a few marine relics in themagnesian limestone 
below it. 

Red mail is the last of the strata or formations, which is 
tolerably conformable as to position with those above it, and like 
them, neatly horizontal ; the strata of the succeeding formations 
are said, in common geological language, to be unconformably 


Outlines of Geology. 35 

placed with regard to the preceding, rising from under them at 
very various angles into lofty mountain chains, skirted by the 
red marl which occupies the extended plains at their base, u go 
that the appearance of the whole may be described by the figure 
of a sea composed of horizontal beds of red marl, &c, surround- 
ing elevated islands, consisting of rocks of the coal formation or 
carboniferous mountain limestone, old red sandstone, slate and 
granite, all variously and irregularly stratified." 

In the red sandstone of Droitwich in Worcestershire, and at 
Northwich in Cheshire, are our most considerable beds of salt : 
at the former place, they are inundated, and form what are called 
brine springs ; at the latter, the solid salt is accessible, and has 
been excavated to a great extent both in width and depth. At 
Droitwich, the brine contains about one-fourth its weight of salt, 
and furnishes upwards of 10,000 tons annually. From this source 
the revenue derives an annual duty of £320,000; a fact, notwith- 
standing the partial advantages that accrue from it, greatly against 
the suspension of that equitable tax. At Northwich the quantity 
of solid salt annually raised exceeds 150,000 tons, about 16,000 
of which are consumed at home, and 130 to 140,000 exported. 

As the Cheshire salt deposits are below the level of the sea, it 
has been conceived that the ocean once covered the districts, and 
there let fall these enormous masses of muriate of soda, and that 
the clay, sandstone, and other substances, have resulted from the 
ruin of older rocks ; but the salt is not such as would be obtained 
by the spontaneous evaporation of sucli water as our ocean now 
contains. Others regard these salt pits as the bottoms of large 
cauldrons, in which sea water has been boiled down by subterra- 
nean heat, and left the bed of salt like the earthy fur upon the 
bottom of a tea kettle : I do not know that there is much choice 
between either of these hypotheses. 

In describing the coal-fields of England, I can only advert very 
generally to their arrangement and contents. The Encyclopedia 
Britannica contains two valuable articles upon this subject, and 
the details respecting the south-western coal-district of England, 
published in the first volume of the second series of the Geo* 

D2 


36 Outlines of Geology. 

logical Transactions, by Messrs. Buckland and Conybeare, may 
be referred to as the best geological history extant of these im- 
portant formations. 

The great northern coal-district of England lies between the 
river Tees (which separates Durham from Yorkshire,) and the 
Tweed, and the country slopes from Crossfell and the Cheviots 
slowly towards the sea, the abrupt faces of those hills being upon 
their western side. The beds of which this coal-field consists 
partake of the general slope of the face of the country, reaching the 
surface on Crossfell, and gradually dipping towards the east, and 
away under the sea. At Sunderland they are covered by magne- 
sian limestone, and they appear to lie in a basin of mountain lime- 
stone, abounding in veins of lead. . . 

The strata of the coal-basin are coal, sandstone, shale, lime- 
stone, and basalt, and they abound in vegetable impressions and 
in fresh- water shells ; among the former, the varieties of fern 
predominate ; among the latter, bivalves like those of the fresh- 
water muscle. It may not be improper here briefly to notice the 
chemical varieties of coal that are presented to us in these dis- 
tricts, especially as relating to their economical applications. 

The coal which is generally most esteemed is that of the' nor- 
thern districts, Northumberland, Durham, and Yorkshire; it 
abounds in bitumen, softens in the fire, swells, and throws out jets 
of flame ; it coheres, and therefore burns hollow and requires 
poking ; it furnishes cinders, though but little ash. On the other 
hand, most of the coal from the west of England blazes and burns 
briskly, being much more easily kindled than the other ; it requires 
no poking, because it has no tendency to cake ; it affords no 
cinders, and leaves a dusty white ash. 

A third kind of coal called culm, or stone-coal, contains scarcely 
any bitumen, and abounds in earthy matter ; it is very difficult of 
inflammation. Besides these, there are some other varieties, such 
as cannel-coal, splent-coal, fyc. 

There is one important circumstance observable in stratified 
countries in general, already adverted to, and more especially 
shown in the coal-beds, which is, that they were evidently depo- 


Outlines of Geology. 37 

sited before many of those unevennesses which give' rise to our 
present hills and dales were carved out upon the surface, and often 
where even a deep and extensive valley intervenes, the same strata 
running in the same direction, and at the same levels, are found 
continuous on both its sides ; except in some particular cases, where 
the valley is very narrow and abrupt, and its sides perpendicular, 
and where it appears to have been formed by the dislocation and 
fracture of the ground, once continuous, in which it occurs. 
. In consequence of the peculiar arrangement of the coal strata, 
a section of them often gives the idea of a basin, or boat-shaped 
concavity, which has been successively filled with the various 
substances that occur in it ; the seams of coal vary in number and 
in thickness, as well as in quality, and the upper seams are ge- 
nerally imperfect. 

In consequence of the dip of the strata, it not unfrequently hap- 
pens that we have an opportunity of examining and ascertaining 
the nature of the lowest seams, which, though deep and out of 
reach in one part of the coal-field, are superficial at another. 
This is shown at Cross-fell, where the crow-coal rises to-day, 
which, in consequence of the inclination of the beds, is considered 
to be nearly 460 fathoms below the lowest of the Newcastle beds, 
a little to the east of that town. 

The description of one coal formation applies, in general, to 
others ; but there are certain circumstances which give peculi- 
arities to some of our coal districts, among which the iron- works 
are deserving attention. The ore which is here worked is the 
clay iron-stone ; an ore poor in itself, but deriving value from the 
abundance of coal that attends it. 

Some writers have amused themselves with speculations re- 
specting the exhaustion of our coal-mines, and have calculated 
the number of years, or centuries, that the stock on hand is likely 
to last. When, indeed, we reflect upon the vast importance of 
this specie3 of fuel in a country dependent not merely for its pros- 
perity, but even for its very existence, upon its manufactures and 
consequent commerce ; when we remember its enormous and in- 
creasing consumption ; when we consider that the metropolis only 


38 Outlines of Geology. 

swallows up annually considerably more than a million of chaldrons 
exclusively from the Tine and Wear districts ; it might appear that 
the apprehensions of some worthy persons upon this score were 
not altogether without foundation. It is however admitted, on 
the other hand, that the Newcastle mines only are capable of con- 
tinuing their supply for another thousand years ; and if this reflec- 
tion is insufficient to satisfy the disquieted minds of those who 
are still uneasy, they may console themselves with the reflection 
that there are many other districts which have only been, as 
it were, begun upon, and probably numerous deposits of which we 
are as yet ignorant, but which will be searched for and found 
when wanted. Besides which, it may, I think, be calculated, that 
of every chaldron of coals consumed in our ordinary fires, about 
one-eighth part is lost in the character of soot, smoke, and other 
unburnt matters; so that in London only, up wards of 100,000 
chaldrons of coals are thus dissipated and unprofitably applied 
to the contamination of our atmosphere, which smoke, by 
improved methods of combustion, might be turned to profitable 
account. 

In speaking of the general arrangement of the coal strata, I 
have said nothing of the dislocations to which they are subject, in 
consequence of what are called troubles, or slips, and dikes ; that 
is, the strata are cut through, broken off, and sometimes thrown 
up on one side, and depressed on the other ; and by the fissures 
and cracks thus produced are filled with broken stones and frag- 
ments of the strata, or with a hard species of rock called a dike, 
near which the coal is converted into a cinder, and from its cavi- 
ties emits those tremendous torrents of inflammable gas, techni- 
cally called blowers. 

To the probable origin of these faults, or dikes, I shall after- 
wards advert more at full ; they record one fact, namely, that the 
coal strata, subsequently to having assumed their present disposi- 
tion and arrangement, have been subject to various disturbing 
causes, breaking their continuity merely in some instances, but in 
others affecting the whole district, and throwing it for hundreds 
of acres together out of its original position. 


Outlines of Geology, 39 

Lastly, as to the sources and origin of coal. Upon these sub* 
jects geologists, as usual, have amply indulged their inventive 
faculties. Every thing tends to show the vegetable origin of coal, 
and a regular succession might be shown, commencing with wood, 
little changed, and ending with coal, in which all traces of organic 
texture are lost. Yet even in the most perfect coal we frequently 
find some relic, some trace of a vegetable, or some remains of 
fibrous texture that announces its ligneous origin. In the leaves 
that occur in Bovey coal, Mr. Hatchett, to whom we owe many im- 
portant observations and experiments upon this subject, found resin 
and extractive matter ; and what is more to the purpose, he found 
a substance having properties intermediate between resin and bitu- 
men, and therefore partaking partly of vegetable and partly of mine- 
ral characters ; and more lately the same substance has been found 
in the principal coal-field of Staffordshire. Perhaps, therefore, an- 
tediluvian timber and peat bog may have been the parent of our 
coal strata, but then, how has its conversion been effected ; is it 
merely by the agency of water, a kind of decay and rotting down of 
the wood ; or has fire been called into action, torrefying the ve- 
getable matter, and has the pressure under which this heat has 
operated prevented the escape of volatile matters, and caused them 
to assume the form of bitumen ; and are those reservoirs of com- 
pressed carburetted hydrogen which I have mentioned as causing 
blowers^ to be ascribed to such mode of formation ? The discussion 
of these subjects might be prolonged, but it would end in nothing 
satisfactory. The theories that have been invented to account for 
our coal formations are full of weak and assailable points ; tho 
further we pursue them, the less do they satisfy us, and the more 
discordant do they seem with the phenomena they are intended 
to explain. 

We should almost conclude, from the dogmatical air of some 
writers upon this subject, that they had seen the agents they 
speak of in active operation ; that they had fathomed the depths 
of the globe, and measured its central heat ; but if we compare 
our planet to an orange, and remember that we have not as yet 
penetrated its rind ; if we compare it to the pasteboaid globe of 


40 Dr. Mac Culloch on a peculiar Appearance 

the instrument-maker, and remember that we have scarcely peeled 
the paper from its surface ; these considerations should alone be 
sufficient to check the presumption of the theorist, and set bounds 
to the arrogance of hypothesis. 


AxtT. VI. On a peculiar Appearance' exhibited by Hoar Frost. 
By J. Mac Culloch, M.D., F.R.S.E., &c. 

[Communicated by the Author.] 
It has long been known that dew, as well as hoar frost, has a ten- 
dency to attach itself to particular bodies, rather than to others, 
and to rough surfaces in preference to smooth. Hence also it is 
found that hoar frost, which, from its permanence, is more easily 
examined than dew, is frequently deposited on acute edges and 
points, when the flat surfaces of the same bodies continue bare. 
I need not notice the speculations which have been entertained re- 
specting the connexion of this phenomenon with electrical agency ; 
but it is also obvious that the attachment of hoar frosts to strings, 
edges, and points, bears a striking analogy to that which occurs 
in many cases of the ordinary crystallization of salts from solution 
in water, where the preference is so often given to bodies of these 
forms as the first bases of attachment. 

The causes which influence this mode of disposition are as 
much unknown as is every thing that relates to this mysterious 
process. It is to little purpose to form conjectures, or to propose 
hypotheses on this subject ; but it is not useless to record any 
facts, which, by their accumulation and ultimate comparison, may 
tend to throw light on it ; and, with this view, I transmit to you 
the enclosed sketqh of a crystallization, or rather a deposit, of hoar 
frost, which is remarkable for its singularity, and which has not, 
as far as I know, been hitherto noticed by those who have paid 
attention to these subjects. As it will tend to save much expla- 
nation in words, and will at the same time render the appearance 
in question much more intelligible, I send you the sketch precisely 
as it was made on the iron railing of the door-way where I at first 
observed it. 


exhibited by Hoar Frost. 


41 


K\\\wiHiiiiiiiiiiiiiiiiimiiiiiiiiiii iiiiiniiii»iii iiiiiiinnniininiiiHiniiiiiiiniiimiimilf 


Section of a bar, with 

the true position of the 

crystallization. 


The crystallization 
magnified. 


The temperature was little less than the freezing point, and 
there was a moderate fog with a high barometer, and an easterly 
wind ; but no other meteorological phenomena were observed, nor 
had I any opportunity of examining the state of the atmospheric 
electricity, beirig far from home, and casually visiting in Portland- 
place, where this sketch was made. 

Although the general effect of the distribution of this deposit 
of ice is sufficiently visible in the drawing, it will require a few 
words of explanation. The points did not consist of single crys- 
tals, but of pyramidal bodies, formed of crystals so minute and 
entangled, that their forms could not be discovered by the lens. 
They were about the sixth of an inch in length, and distant from 


42 Dr. Mac Cullouh on a peculiar Appearance 

each other by a space equal to the breadth of their bases ; con- 
jecturally, about the 30th of an inch. Where they were attached 
to the salient angle, or edge of a bar, they were at right angles to 
its line, and at the same time equidistant at the summits from each 
of the including planes, so as to form an angle of 45 degrees, 
with their surfaces on each hand. This distribution was main- 
tained in the same manner in those parts of the iron-work which 
consisted of curved or circular parts ; so that each group, or pyra- 
mid, was invariably placed at right angles to the tangent of the 
curve at that part, or in the direction of the radius of curvature. 
Hence it appeared, at first sight, that the effort of each pyramid 
consisted in an attempt to recede as far as possible on each hand, 
not only from the planes, but from the edge ; and thus to attach 
itself at right angles to the Utter. The same effect also took 
place in the interior as in the exterior of the curved parts ; and 
thus the whole was ciliated like the leaves of some plants with a 
regular and beautiful fringed work. 

The singularity of this appearance exciting my attention, I was 
induced to examine it more narrowly, for the purpose of seeing how 
the pyramids would dispose of themselves among the more intri- 
cate parts of the iron-work. It was found, in consequence', that 
where any two edges of a bar met at right angles, the crystals 
formed at an apex occupied the direction of the diagonal of the 
cube which was formed by the union of the bars, or maintained a 
distance equally removed from the edge of the joint on the one 
hand, and from the plane at right angles to it on the other. But 
the crystals on the two meeting edges, where nearest to the apex, 
did not immediately assume a rectangular position towards these 
edges ; diverging gradually in succession from that on the angle 
till they assumed the regular position which they held on the re- 
mainder of the edge. 

In the re-entering, or internal angle of the same joints, the 
crystal of the angle was also prolonged according to the diagonal 
of the cube ; and here the crystals, intermediate between that and 
those which stood at right angles to the internal edges at a short 
distance, were so arranged as, in maintaining an equal distance at 


exhibited by Hoar Frost. 43 

their bases, not to touch at their summits. Thus they all con- 
verged for a short space round the interior diagonal crystal, as, on 
the exterior, they diverged from it, in the manner represented in 
the sketch. 

Where two planes met at a right angle, similar arrangements 
took place ; the crystals, whether on the external, or within the 
internal angle, occupying a direction equidistant from the planes 
on each side. 

This arrangement equally occurred when the angles of meeting 
of approximate edges or planes were greater Or less than right 
angles, the equidistant position being regularly preserved ; while, 
in the case of the interior angle formed by planes, any contact of 
the summits of the crystals was invariably avoided. Hence in 
those cases where very acute interior angles happened to exist, 
the crystals became so shortened, for the purpose of avoiding a 
contact between those on the neighbouring edges, that, near the 
extreme point, they at length vanished. 

In all other more complicated cases of the meeting of the parts 
of the iron-work, the same general rules were found to prevail. 
In every part, in short, however intricate, where the crystals were 
formed, they seemed endued by a repulsive power, in consequence 
of which they tended as far as possible to recede equally from all 
the plane surfaces and edges in their vicinity, and, at the same 
time, to avoid any contact with each other. 

It will be suggested that this repulsive property depended on 
some electrical condition, as we are not acquainted with any other 
power by which it can be explained ; but it is not easy to assign 
that modification, or mode of action of this mysterious power, by 
which the effect could have been produced. I cannot pretend to 
suggest any solution of this appearance, and am better pleased to 
leave it thus recorded among the numerous insulated and inexpli- 
cable facts in science, of which the explanation will at some future 
time appear as simple as it now seems difficult. 

I need only add that, on the same forenoon, all the iron rail- 
work, whicli I examined for this purpose, between Portland- 
Place and Great George-Street in Westminster, exhibited the 


44 Appearance exhibited by Hoar Frost. 

same appearance ; but that I had never observed it before, and 
have never seen it since the winter of 1818, when this note was 
made. 

The sketch only pretends to represent the general effect of this 
appearance to the eye. To have given the true position of the 
crystallization with respect to the sides of the bars, would 
have required a more highly finished engraving than was here 
admissible. A section of a bar is added for that purpose. All 
those intricate appearances, which it was thought unnecessary to 
represent, may easily be understood from the -description. 


Art. VII. A Letter from A. Copland Hutchison, Esq., 
to Sir Everard Home, Bart., containing an Account of a 
successful Case of the High Operation for the Stone. 

[Communicated by Sir Everard Home, Bart.] 

Bear Sir, 8^ August, 1825. 

As your two successful cases of the high operation for the stone, 
published in the third vol. of Strictures, have encouraged me to 
adopt that mode of operating ; and finding, also, that you have 
since that time operated in the same manner twice at St. George's 
Hospital ; these being the only cases, I believe, that have occurred 
in England since the days of Cheselden*, I am induced to send 
you an account of the following case and operation, with full per- 
mission to make any use of it you may think proper. 

* In one case upon a man 54 years of age, October 29th, 1824, in which the 
stone was'extracted entire, weighing about 3| ounces, though its texture was so 
loose beneath the external crust, that it afterwards broke to pieces in the 
hands of a gentleman who was examining its surface. In this case the patient 
died on the third day after the operation ; but upon examination after death, 
the operation, in itself, was not the cause, the bladder having suffered so 
much by disease from the presence of the calculus, as not to admit of his 
recovery. 

The other case was a boy eleven years of age ; the operation was performed 
on the 3rd December, 1824, and the patient got well, though the wound, from 
his bad state of health, did not completely heal for two months. From his 


High Operation for the Stone. 45 

Mr. C. aged 20, the son of an officer of Slieerness dock -yard, 
had laboured under symptoms of stone from his earliest infancy, 
and was twice sounded between the age of five and six, by a dis- 
tinguished surgeon in London, but who was unable to satisfy 
himself of the presence of a calculus in the bladder. The patient 
and his father informed me that throughout his whole life he had 
never been able to retain his urine more than half an hour, night or 
day ; the pain was occasionally so severe, also, in these frequent 
acts of micturition, that his life had become burthensome to him ; 
and before this act could be effected in childhood, they were some- 
times under the necessity of placing him on his head. 

These symptoms continuing without any abatement, he con- 
sulted me about three months ago, when, on passing the sound, a 
calculus was discovered. Under these circumstances I determined 
to perform the high operation, and indeed there seemed to be no 
choice left; first, because I considered the stone to be too large 
for extraction by the lateral operation ; and, secondly, because the 
bladder could not bear distention, for it never had been distended 
sufficiently with urine, to enable anyone to perform the lateral ope- 
ration with safety to the patient, and satisfaction to the surgeon. 

The patient having been kept upon low diet for a month, his 
bowels frequently acted upon by purgative medicines during that 
period, and the bladder purposely made accustomed to the frequent 
touch, and sometimes rather rough treatment with the staff, the 
operation was performed on the ISth June, 1825, in the following 
manner, and in the presence of Dr. Lewis and Mr. Malin, of the 
army, and of Messrs. Brown, Cullen, and Keddell, surgeons, of 
Sheerness. The patient being placed on a mattress upon a table 
of ordinary height, with a pillow under his head ; rf the pelvis raised 
considerably higher than his shoulders, with the view of removing 
the peritoneum as far from the parts to be cut as possible, while 

birth the water had always dribbled from him ; the stone was small and sphe- 
rical, and its external surface made up of spiculated crystals. 

I have added this note from your letter to me, with a view that all the ope- 
rations of the kind which have come to my knowledge may be recorded 
together. 


46 Mr. Hutchison on the 

his feet rested upon chairs ; standing on the right side of the pa- 
tient, I made an incision, nearly four inches in length, with a 
scalpel, in the line of the linea alba through the integuments 
downwards over the front of the pubes, which latter step I found 
of great advantage both during the operation and in the subse- 
quent treatment of the case. The incision was carried on down 
towards the bladder, between the pyramidales muscles, and 
through the linea alba ; the latter being first punctured, and after- 
wards cut transversely upon the symphysis pubis, dividing some of 
the fibres of the pyramidal muscles on each side as we proceeded, 
so as to give a more free passage for the extraction of the stone. I 
then, with a director, detached this tense membrane (the linea alba) 
from its subjacent adhesions, and divided it upwards with a probe- 
pointed bistoury, introduced into the groove of the director, until I 
could readily insert the forefinger of my left hand, which is, on all 
occasions, the best director, and which was most conveniently done 
by standing between the legs of the patient. "When about two 
inches and a half of the linea alba were thus divided, I thought we 
should have had sufficient space for cutting into the bladder and 
extracting the stone ; but as the wound appeared deep and narrow, 
and there Was a large calculus to extract, I cautiously extended the 
incision half an inch more, in the manner already described. 

The bladder, very much contracted, was now clearly seen 
covered by fat, and was raised through the fat, upwards and 
forwards, to the external wound of the integuments upon the 
point of a silver staff, with a groove in its concave part, extend- 
ing from close to its point downwards about two inches, and 
which I preferred to the sond used by the French surgeons, 
that instrument appearing to me both unnecessary and unsci- 
entific : the handle of the silver staff being held in a depressed 
position by my friend Mr. Brown, the anterior part of the fun- 
dus of the bladder was pierced from without, by a straight sharp- 
pointed bistoury, passing its point into the groove of the staff, 
and carrying the incision downwards and forwards to the 
pubes, until there was room for the fore-finger, which was intro- 
duced for the purpose of ascertaining the size of the calculus, that 


High Operation for the Stone. 4? 

the opening in the bladder might be enlarged accordingly. Hav- 
ing satisfied myself on this head, I hooked up the fundus of the 
bladder with my finger, and enlarged the incision towards its 
cervix, sufficiently to admit of the free extraction of the stone. 
Some little difficulty here arose in disengaging the stone from its 
situation, notwithstanding the great assistance obtained by the 
introduction of the fore-finger of my right hand into the rectum, 
while the fore-finger of my left was in the bladder to cant or turn 
the stone, so as to extract it by its smaller axis ; and, indeed, this 
was not effected until the single blade of a pair of small stone 
forceps was introduced. The stone being thus turned, it was 
easily removed with the finger and thumb. In point of fact, so 
firmly did the bladder grasp the calculus, that the idea was con- 
veyed to our mind of its actual adhesion to the coats of that 
viscus. 

One small cuticular artery was divided at the first incision, and 
secured at the time, to prevent the future steps of the operation 
being obscured by the bleeding, and the subsequent issue of blood 
into the cavity of the pelvis. 

Two slips of linen, dipped in oil, were introduced through the 
external wound on each side of the bladder, but not into the bladder , 
as was done in your first case, published in the Philosophical 
Transactions * ; a gum elastic catheter was passed into the bladder 
so as just to enter its cavity, and no farther, and was secured 
in this situation by tapes attached to the instrument, and to 
an elastic band, or retainer, in the manner described in your 
paper, but which in this case was made of flannel, lined with 
calico. The sides of the wound were brought together by 
slips of sticking plaster, and the parts supported by a flannel 
roller, passed three or four times round the pelvis and the lower 
part of the abdomen. The patient, by means of pillows, was 
placed on an inclined plane, a vessel was secured to the end of 
the catheter to receive the urine, and he had an anodyne draught 
administered to him. 

• Afterwards republished in your third vol. of Strictures. 


48 Mr. Hutchison on the 

I am fully aware that there are those who may imagine the. 
trifling difficulty we experienced in extracting the stone, arose 
from the depth, narrowness, and consequently from the supposed 
tightness, as it were, of the wound, through the parietes of the 
abdomen ; but I can assure them that such was not the fact, for I 
enjoyed the most perfect freedom in that respect. The circum- 
stance in my mind arose rather from the position of the stone, its 
size, and the strong contraction of the bladder upon it ; for it will 
be borne in recollection that the bladder, in this case, had never 
been distended beyond the size of the calculus, and that which two 
ounces of urine would occasion. What the bladder wanted in ca- 
pacity, it possessed in the increased thickness of its parietes, for 
it was fully a quarter of an inch thick at the part divided ; so that 
its muscular power must, therefore, have been considerable. I 
cannot avoid, in this place, repeating the great advantage to be 
derived from dislodging the stone, in such cases, by the introduc- 
tion of the finger into the rectum, and which appears to me a 
great improvement in this mode of operating. 

19th June. Slept two hours during the night ; about six ounces 
of urine came through the catheter, the rest by the wound. His 
pulse this morning was 120, and full ; he was bled, therefore, to 
twenty ounces^ and I prescribed saline draughts every three 
hours, each containing ten drops of liquor antimonialis. He was 
otherwise free from pain, and only complained of a smarting 
in the wound. 

20th. Had four hours continued sleep during the night, for the 
first time in his life : urine passed equally by the instrument and 
the wound: pulse about 100, and soft, and he perspired profusely 
during the night : the draughts were continued, and he was sup- 
plied with barley-water for his common drink; An aperient 
draught was prescribed for the following morning. 

21st. Slept nearly six hours last night : pulse 90 : skin moist : 
no pain whatever : his bowels were well moved by the draught : 
urine passed as the day before, and he sat up about two hours, 
with his feet hanging over the side of the bed, and resting upon a 
chair. 


High Operation for the Stone. 49 

No one bad symptom occurred afterwards : the urine continued for 
about five weeks to come occasionally by the wound in small quan- 
tities, the rest by the natural passage : the wound itself continued 
to look healthy from the first, and gradually closed until the 31st 
July, when it was completely healed, and the patient voided his 
urine in a full stream through the urethra. 

Thus terminated this successful case; and, I am strongly in- 
clined to believe, that the patient's recovery would have been still 
more speedy, had the catheter been sooner altogether withdrawn 
from the bladder; for it was retained almost constantly in that 
situation about three weeks, removing it night and morning only, 
for the purpose of clearing it of mucus. 

The stone weighed eleven drachms two scruples and four grains. 
It is two inches long and one inch and half in width. A section 
has been made of it, and my friend Dr. Prout has had the kindness 
to analyze it for me. The result will be found in the Doctor's note 
addressed to me. 

I have the honour to be, 
Dear Sir, 

Your very obedient humble servant, 


A. Copland Hutchison. 


To 

Sir Everard Home, Bart., 

Sfc. Sfc. 8fc. 

Sackville- Street. 


London, July 12. 
My dear Sir, 

The nucleus of the calculus whicli you were kind enough to 
leave for me, consists essentially of the lithate of ammonia, mixed 
with some oxalate of lime, (and probably a little carbonate of 
lime,) the phosphates, and animal matter. The exterior laminae 
are chiefly composed of the phosphates ; but two or three small 
fragments detached from the surface were found to consist chiefly 
of the phosphate of lime ; and this circumstance made me anxious 

Vol. XX. E 


50 High Operation for the Stone. 

to see the urine, as I had never before known this salt deposited 
alone from that secretion, and hence had been led to believe that 
calculi composed entirely of that substance were not of urinary 
origin, but formed in a manner analogous to those met with in the 
prostate gland. 

The specimens of urine which you were good enough to send 
me arrived in safety, but I am sorry to say that they throw no 
light on the subj&ct, or rather on the point in question. They 
are alkaline, and of a very bad character, and abound in the 
mixed phosphates, (that is, the phosphate of lime and the triple 
phosphate of magnesia and ammonia,) as is usual in such 
cases. 

I am, my dear Sir, 

Yours, &c. much obliged. 
W. Prout. 
40, Sackville- Street. 


Art. VIIL On Calcareous Cements. By 

John White, Esq. 

j 

[Communicated by the Author.] 
To the Editor of the Quarterly Journal. 
Sir, 

In the Miscellaneous Intelligence contained in your last number, 
you have remarked, that you should take notice of such facts 
respecting the theory and improvement of calcareous cements as 
were brought to light at different times, with the fair conclusions 
to be drawn from them, being convinced, in the highest degree, of 
the importance of the subject, and of the advantage which the 
investigation must lead to, 

Having for nearly thirty years experienced, practically, the im- 
perfections of the various cements in use in England, I have been 
led into a variety of examinations of them, and do not hesitate to 
communicate to you an account of a series of experiments which 


Mr. White on Calcareous Cements. 6\ 

will, in my opinion, contribute essentially to a knowledge of the 
subject. 

The first endeavour at investigation was made by a comparison 
of various burnt clays, obtained in the neighbourhood of London 
and in Kent, with the imported Pozzolano, as sold in London ; but 
the imported material was so variable in its nature, that little re- 
sulted beyond a knowledge that it possessed more calcareous mat- 
ter, and that it was more uncertain and variable in the sizes of the 
grains, than that of British manufacture. 

The next endeavour was to ascertain what, practically, were 
the best sizes of the particles to be used with lime, and in what 
state and what species of lime entered best into the combination 
with them. 

It appeared that either the foreign or British ]PozzolanQ, if re- 
duced into a very fine powder, lost considerably its power of adhe- 
sion, though it was more plastic. It necessarily was inferred, that 
the greater the variety of dimension of the particles, the greater 
would be the entanglement of the asperities, and, consequently, the 
greater the adhesion. Of the mortar made, it also appeared that 
the finer the lime could be ground, the more perfect would be the 
combination, and the harder the mortar obtained, because the 
hard particles of the Pozzolano being in a state of actual contact, 
no compression was likely to take place ; and which, in fact, upon 
the subsequent investigations proved to be the case. 

My reasons for trying the Pozzolano were these. I conceived 
that I should have two causes for the induration of the mortar ; 
one, the disposition which many burnt materials have to unite in- 
timately with lime ; the other, the variety of form which the frac- 
ture of burnt clay produces ; the real difficulty which existed was, 
the obtaining a perfect knowledge of the best state, and the best 
mode of indurating properly the clay itself. For if the burning of 
the clay were such as to cause vitrification, an imperfect mortar 
was made ; perfect glass, scoria, and pumice-stone, produced very 
inferior mortar ; perfect Pozzolano appeared to be made when a 
chalky clay was so indurated by fire as to put on the appearance 
of a commencing vitrification only. 

E 2 


52 Mr. White on Calcareous Cements, 

■ 

First Experiment, tried August 9, 1 824.. 

A pier, three feet four inches wide, one foot ten and a half 
inches thick, five feet eight inches high, was built on the 9th July, 
1824, and was composed of hard sound London burnt stock- 
bricks, and mortar of one part ground lime, one and a half parts 
sand, and two parts rough Pozzolano. It was elevated by applying 
screw-jacks on each side, course by course, beginning at fifteen 
courses, or three feet nine inches from the bottom ; this elevation 
from its foundation took place without any separation of the 
courses until the screw-jacks were placed two courses, or six 
inches from the top, when these two courses separated from the 
remainder of the pier. 

The remainder of the pier was then thrown down, when it se- 
parated at eight courses from the foundation, and exhibited that 
the middle was not dry. 

This experiment was tried in the presence of Mr. Brunei, 
Mr. Mathew Wyatt, Mr. Smith, and many other gentlemen. 

Second Experiment, April 21, 1825. 

A pier of thirty-five courses of brickwork high, being six feet 
wide, three feet thick, and eight feet ten inches in height, was built 
also July 9th, 1824, of hard sound London stock-bricks, and of a 
cement composed of three parts British Pozzolano, ground and 
sifted, having particles, none being bigger than one-eighth of an 
inch, and one part of ground Dorking lime, unslacked, fresh mixed. 
This pier was first elevated from its base by a strong chain, grap- 
pling it at nine courses of brickwork from the top, again in the 
same way at six courses from the top, and at last the whole pier 
was suspended by a set of Lewis's, let into the middle of the top of 
the pier, about fifteen inches deep ; the weight of the pier was 
about nine tons. 

This experiment was tried in the presence of Mr. Brunei, Sir 
Thomas Baring, Admiral Sir Edward Codrington, Colonel Lowther, 
Mr. Smirke, Dr Chumside, and nearly two hundred spectators. 


Mr. White on Calcareous Cements. 


53 


Third Experiment, made May 12, 1825. 

It having been suggested by Mr. Brunei, and Mr. Smirke, that it 
would be useful to try the comparative adhesive properties of these 
cements by building other piers of such dimensions as might enable 
them to be laid horizontally, and have weights placed on them in 
the middle, nine piers were constructed on the 21st and 23rd 
April, in a vertical position, and of the following dimensions, viz., 
six feet high, and about fourteen inches square. 

The First Pier (A) which was tried was of pure fresh Roman 
cement, and was accident ly broken in laying down where the ce- 
ment had partially set in the joint of brickwork before the adhesion 
had taken place. A fragment of the pier, three feet six inches in 
length, being laid down as here represented, 

A 


< 30 en: f 


was carefully loaded at A with weights half a hundred at a time ; 
it supported eleven hundred weight, and broke under eleven and a 
half hundred weight. 

The Second Pier (B) was composed of three parts Pozzolano and 
one part stone lime, reduced to putty as common mortar. This 
pier was similarly placed in the supports, it broke in the middle, 
and a fragment was similarly loaded, when it supported four hun- 
dred weight, and broke under four and a half hundred weight. 

The Third Pier (C) three parts Pozzolano, and one part stone 
lime, ground and fresh. This pier broke in turning it round, and 
the fragment laid by, for further experiments. 

The Fourth Pier (D) three parts pure sharp sand, and one part 
stone lime. This pier broke into three pieces on attempting to 
lay it on the supports. 

The Fifth and Sixth Piers (E F) of three parts sharp washed 


34 


Mr. White on Calcareous Cements. 


sand, one part chalk lime, crumbled to pieces on attempting to 
place them. 

The Seventh Pier (G) was composed of Atkinson's Roman ce- 
riient one part, pure sand one part. 


-A- . 


■ B 


H *f frrr 


\ 


Weights being carefully and successively applied at A, half a 
hundred at a time ; it supported five hundred weight, and broke 
under five and a half hundred weight at B ; on examining the 
separated parts, it was evident that the mortar had not equally 
adhered to every brick 

The largest end being tried in the same way as in the first ex- 
periment, viz. 


It was left nearly half an hour with one ton weight at A, and 
broke in consequence of a shock it experienced by the breaking of 
the pier subjected to the next experiment. 

The Eighth Pier (H) four parts Pozzolano, and one part air- 
slacked stone Mme. This broke in laying down. A second expe- 
riment was made as in the preceding pier, itf supported five and a 
half hundred weight, and broke in two pieces. 

The Ninth Pier, built of rough lumps of Pozzolano, in imitation 
of Roman walling, nine parts Pozzolano, and one and a half parts 
stone lime, was not sufficiently dry to be experimented upon. 


Mr. White on Calcareous Cements. 


Continuation of Experiment No. It. May 12th. 

Two wrought-iron wedges 
were driven with sledge 
hammers at X X, for the 
purpose of splitting this 
pier ; it resisted very long, 
and when separated, it 
was found that many 
bricks had not taken the 
mortar. 

The mortar was not 
completely dry, it would 
require another sum- 
/ mer to give it all the 
toughness and tenacity it 
can acquire. 
The same wedges were afterwards driven with the same ham- 
mers, and greater effort at A A. It resisted and repelled the 
wedges several times, but when separated, the mortar and bricks 
appeared to have resisted alike. 

A third attempt was made by driving the same wedges at B B, 
when a new separation took place, exhibiting the same appearance 
as in the first separation. 

This experiment was made in the presence of the Earl of 
Southampton, Mr. Brunei, Lieutenant-General Sir Alexander 
Bryce, and many others. 

Fourth Experiment, May 20, 1825. 

The adhesion of the materials being, in some measure, ascer- 
tained by the foregoing experiments, it appeared desirable to learn 
how far the application of weight vertically would effect them, 
when the following trials were made at Mr. Bramah's, at Pimlico, 
by subjecting portions of the above piers to the hydrostatic press. 

First Trial, Pier A. Roman cement. — Section one hundred and 
ninety-six inches superficial, cracked with 4S,960 lbs., the 


56 Mr. White on Calcareous Cements. 

compression being continued until it was entirely destroyed with 
92,160 lbs. or 41 tons, 320lbs. 

Second Trial, Pier (B) Pozzolano three parts, lime one part. — 
Section one hundred and eighty inches superficial, this being over- 
laid with sand at] top, the same escaped compression, so that the 
result was uncertain. 

Third Trial, Small fresh-built pier nine inches square, Pozzo- 
lano three parts, ground lime one part. — Compressed a very little 
with 18,720 pounds, entirely destroyed with 24,480 lbs., section 
eighty-one inches superficial. 

Fourth Trial, (G) Atkinson's Roman cement and sand, equal 
measure. — Cracked on two sides with 37,440 lbs., entirely de- 
stroyed with 80,640 lbs., section one hundred and ninety-six 
inches superficial. 

Fifth Trial, (H) Pozzolano four parts, lime one part — Cracked 
with 28,800 lbs., fracture increased with 48,960 lbs., entirely 
destroyed with 51,840 lbs. 

Sixth Trial, (C) Pozzolano three parts, Dorking lime one part. — 
Fractured one side with 31,680 lbs., fracture increased with 
43,200 lbs. ; fracture again increased with 48,960 lbs. ; this expe- 
riment was not pursued until the pier was entirely destroyed, &s in 
the preceding one. 

Seventh Trial, (D) sand three parts, one part stone lime putty. — 
Compressed on application of weights one-eighth of an inch, 
cracked with 40,320 lbs., fractured in five places with 46,080 
lbs., which entirely destroyed it. 

EigMi Trial, Pier of Portland stone fourteen inches by 12 inches, 
two feet seven inches high. — A sudden fracture was produced 
which divided the stone into two pieces in the centre of the widest 
side with one hundred seventy-three and a half tons ; the upper end 
of the stone was bedded in Pozzolano, which was compressed into a 
cake of five-eighths one -fifteenth thick, in a wet state ; which cake 
remained quite solid after the fracture of the stone. 

These trials were made in the presence of Mr. Smirke, Mr. 
Brunei, Lieutenant-General Sir A. Bryce, Mr. T. L. Donaldson, 
and many other gentlemen. 


Mr. White on Calcareous Cements. 57 

Inferences from the foregoing Experiments. 

It may be inferred from the foregoing experiments, that an im- 
portant adhesion of brickwork had taken place by the use of Poz- 
zolano, sand and lime, in the short period of thirty days. 

That from the use of Pozzolano and lime in the proportions spe- 
cified, almost all the advantages required from a good building 
cement were obtained. 

That Lord Mulgrave's or Atkinson's cement had, in the short 
period of twenty-three days produced an induration which was 
sufficient to maintain almost any weight brickwork was capable of 
for openings in buildings ; the effect probably would have been the 
same in Parker's, had the material not set before the bricks were 
fixed in it, further, that Pozzolano had not, in that period, produced 
an equal adhesion, and that common mortar had produced hardly 
any; and it appears from the splitting of the large piers thrown 
down on the 21st April, that an increasing induration took place ; 
this was evident from the nearly equal fracture of the bricks and 
cement. 

The incompressibility of mortar being one of its most material 
qualities, it results that Parker's, Mulgrave's, and Pozzolano, are so 
far equally useful, that brickwork composed with them will bear 
on each superficial foot before the bricks will crack, about twenty- 
three tons, that fifty tons will totally crush such brickwork ; and 
that Portland stone, of the best quality, will not split with less 
than one hundred seventy-three and a half tons, and that a bedding 
or joint of Pozzolano mortar is not destructible with that weight. 

Art. IX. Remarks on Phytolacca Dodecandra, or, the 
Mustard Tree of the Scriptures. By John Frost, F.L.S., 
Member of the Royal Institution, &c. 

[Communicated by the Author.] 
The remark in the sacred volume *, that a grain of mustard 
seed should become a tree, must have appeared to many very pa- 

* Luke, chap. 13, ver. 19, " A grain of mustard seed which a man took and 
cast into his garden : and it grew and waxed a great tree, and the fowls of the 
air lodged in the branches of it." It 


58 Mr. Frost on the Mustard Tree of the Scriptures. 

radoxical; for what we know under that name is procured from 
an annual plant, (sinapis nigra of Linnaeus,) which has an herbace- 
ous stem, and never attains a greater height than three feet ; there- 
fore it is quite evident that that cannot he the plant referred to, 
the word KtJpM, which is used, implying a shrub, or tree, and 
of course not any plant like sinapis nigra, with an herbaceous 
stem. I am not acquainted with any species of sinapis that can 
be called a shrub, much less a tree. 

The author of a Theological Dictionary, of some repute at the 
present day, has stated under the article mustard seed, that the 
mustard tree alluded to by our Saviour was a species of sinapis, 
and asserts as a proof of the correctness of his definition, the fruit 
of all the members of that genus having a cruciform corolla. 

The plant most likely to be the mustard tree of the Scriptures 
is a species of Phytolacca *, which grows abundantly in Palestine ; 
it has the smallest seed of any tree in that country, and attains as 
great an altitude as any. This circumstance, together with that 
of its being indigenous to the place where the observation was 
made, are sufficient to convince us of the identity of the tree 
referred to. In addition to which I can adduce two facts which 
will greatly tend to confirm this opinion. 

The first is, that of the Americans using the fresh sliced root of 
Phytolacca Decandrat for the same purpose as we use mustard 
seed, viz., that of a Cataplasm. I have been informed that they 
call it (P. decandra,) wild mustard. 

The second is, that of the seed of a species of Phytolacca afford- 
ing what the seed of sinapis nigra does in great abundance, ni- 
trogen ; an element not found in many plants, excepting those 
which belong to the natural orders Cruciatae and Fungi. These 

It may here be proper to state that the term trwa-ruus a ffwavi, in the original 
language of the New Testament, does not signify the seed which is obtained 
from any species of the genus which we know hy the term Sinapis. 

* Phytolacca, derived from <pvrev, a plant, and lacca, or lac, a gum resi- 
nous exudation, of a red colour. The petioles of every species of Phytolacca, 
which I have seen, have a degree of redness, more or less. 

t This is a perennial herbaceous plant, a native of Virginia, occasionally 
found in our gardens under the name of the American Soke-Weed. 


Mr. Frost on the Mustard Tree of the Scriptures. 95 

two facts prove the analogy between the properties of the genera 
Phytolacca and Sinapis. Linnaeus, in his Materia Medica, points 
this out very clearly. 

It appears that the mustard tree of the Scriptures is undoubtedly 
a species of Phytolacca, most probably P. dodecandra of Linnaeus. 
I cannot be quite positive as to the species, as the plant which is 
the subject of this communication has not yet flowered. 

29th August, 1825. 


Observations on an Emetic Oil termed " Pinhoen Oil." 

An expressed oil has just been sent to me from the Brazils, under 
the name of Pinhoen oil. It is used there as an emetic, and acts 
powerfully in the small dose of one or two drops. 

It appears to be procured from the seed of a species of Jatropha, 
of which there are several indigenous to South America, most 
likely J. multifida, the fruit of which has been long known 
under the appellation of the French Physic-Nut. From some ex- 
periments which I made about two years since on the seeds of 
several species of Jatropha, I am inclined to think that there can 
be but little doubt of the plant which yields this emetic oil being 
of the genus just mentioned. And it may here be remarked, that 
the expressed oil of the seed of very many species all produce 
emetic and cathartic effects ; the former attended by a sensation 
of heat about the fauces, and by doubling the dose, drastic pur- 
gative effects ensue. 

Mr. Reeves, of Canton, informed me that the varnish which the 
Chinese are so famous for making for covering paper boxes, tea 
chests, 4*0., is formed by boiling the expressed oil of the seeds of 
Jatropha curcas, with oxide of iron. The seeds of J. curcas have 
frequently been mistaken for those of Croton tiglium, only, one 
can suppose, from there being a degree of analogy between their 
effects, as there is none in point of appearance. 


**tw 


fr+ / *+- - IV<C* 


60 Mr. Swainson on the 

Art. X. A Monograph of the Genus Tachyphonus ; a 
group of Birds belonging to the Tanagrce of Linnaeus. 
By William Swainson, Esq., F.R. and L.S., fyc, 

[Communicated by the Author.] 

The new objects in the higher departments of zoology continually 
coming before us, have, on many occasions, confirmed the justness 
of those views which have led to the formation of new divisions. 
Several of the genera, proposed but a few years ago by the conti- 
nental ornithologists, and which were then supposed to rest on 
the authority of a solitary example, have since been augmented by 
a host of others, hitherto unknown to naturalists, or indiscrimi- 
nately scattered in different genera of the Linnsean system. 

On the other hand, several of these groups, either from not hav- 
ing attracted particular attention, or from no new examples having 
been brought to light, remain confined within their original limits. 

M. Vieillot has given the generic name of Tachyphonus to the 
fifth division of the Linnsean Tanagers, as arranged by that acute 
ornithologist M. Desmarest, and in which is comprised only two 
species, the Tanagra nigerrima of Gmelin, and the Tanagra 
cristata of Linnaeus ; both natives of South America. During 
my residence in Brazil, I was fortunate in procuring several other 
species, evidently belonging to this group, and which seem to be 
hitherto unrecorded. This latter point, however, is doubtful ; for 
within the last few years the provinces of Brazil have been tra- 
versed in almost every direction, by many learned and indefatiga- 
ble naturalists, who are now occupied, under the patronage, and 
even at the expense of the continental governments, in publish- 
ing ample and richly illustrated accounts of their extensive dis- 
coveries in every branch of natural science. Under these circum- 
stances we must receive all descriptions of the productions of 
Brazil, so far as their novelty is concerned, with a certain degree 
of doubt. In the absence of an extensive and public zoological 
library, few of these costly works are accessible, and the treasures 
collected in many of them do not appear till after an interval com- 


Genus Tachypkonus, 61 

mensurate with the care and expense employed to render them 
worthy of their immediate patrons. If this be well understood, I 
see no reason why we should withhold the contribution of our mite 
towards the general stock of knowledge, under the apprehension 
of doing that imperfectly, which others may have previously done 
well ; and with the possibility that, after all, the materials for 
such a contribution may rest alone with ourselves. 

I am unprepared to offer any detailed remarks on the situation 
whicli Tachypkonus may be supposed to occupy among the Tanagrce. 
By its strong, conic, and somewhat lengthened bill, and by the 
sinuosity of the margin of the upper mandible, this group seems 
to have a close affinity with Pyranga. Some species * in which 
the bill is much shorter and proportionably thicker, might, at first 
sight, be mistaken for Fringillce ; while in others t, the fonn of 
this organ is considerably modified, and resembles that of Tanagra 
velia> and its allies. But the typical species J are more particu- 
larly distinguished by the elevated base of the bill, which is car- 
ried on towards the crown, and divides the frontal feathers. This 
character, so much developed among the Icteri of the new world, 
and, in a less degree, among the African weavers, probably in- 
duced the writers of the last century to associate the type of this 
group with the Linnaean Orioles. 

We have little or no information respecting the manners or 
economy of these birds ; judging from the hardness and general 
strength of the bill, the margins of which are frequently infleaed, 
we may suppose that they feed principally upon seeds ; but, in 
some species §, the base of this organ is widened, and the bristles 
of the rictus are sufficiently lengthened to indicate a partially in- 
sectivorous disposition. 

The colour of the plumage is frequently an obvious, though not 
an essential, character in natural groups. In Tachypkonus it is 
usually black, or of one uniform tint on the upper parts, unbroken 
by spots, and unrelieved by those beautiful colours which so orna- 
ment many of the Linnaean Tanagers. Nevertheless the head 

* Tachypkonus itibescens. T. fringilloides. t 71 Desmaresti. T. tenuirostris. 
% T. nigerrimus. T, olivaceus. T. Vigorsi. § T. Suchi. T, cristatut. ? 


62 Mr. Swainson on the 

(in many species) is adorned by a crest of bright red or yellow 
feathers, of a thin and delicate texture, which may be erected or 
concealed at pleasure. A similarly-formed crest is likewise seen 
in some few species of the neighbouring genus Pyranga : but 
among the other Tanagrce it is entirely wanting. 

TACHYPHONUS. Vieillot. 

Rostrum elongato-conicum, validum, lateribus compressis, marginibus in- 
flexis; mandibular superioris margine sinuato, apice emarginato. 

Alee rotundata?, remige primo brevissimo, tertio quartoque paribus, longis- 
simus. 

Cauda rotundata, rectricibus latis. 

Tarsi breviores, squamis lateralibus inlegris. 

Caput fere cristatum. 

Bill lengthened-conic, strong, laterally compressed, base with 
weak bristles, margins inflexed ; margin of the upper mandible 
sinuated, the tip notched. 

Wings rounded, the first quill shortest, the third and fourth 
longest, and of equal length. 

Tail rounded ; the feathers broad. 

Tarsi rather short ; the lateral scales entire. 

Head generally crested. 

1. Tachyphonus nigerrimus. 
T. ater; tectricibus minoribus niveis (maribm) ferrugineis (faeminis.) 
Deep black ; lesser wing covers snowy, (male). 
Entirely ferruginous, (female). 

Tangara nigerrima, Gmelin. p. 899. 

Tangara roux et Tangara noir. Buffon edit. Sonnini, torn. 48, p. 290. 

Le Tangara noir. Desmarest. pi. 45, (mas.) pi. 46, (foem.) 

Tangara noir PI. Enl. 179 f. 2. male. 

Oriolus leucopterus. Latham Ind. Orn. (mas.) Shaw's Zool. 7, 433. 

White-winged Oriole. Lath. Synopsis. Shaw's Zool. 7, 433. 

Total length 7, bill from the rictus fa, wings 3|, tail 3|, 
tarsi ■&, 

This bird, considered by M. Vieillot as the type of the group, is 
too well known to require a detailed description. The young 
males of the first year are clothed in the ferruginous coloured 
plumage of the other sex. 


Genus Tachyphows. §3 

T. nigerrimus seems to be a common inhabitant of the equinoc- 
tial parts of South America. I found it at Pernambuco, and it 
appeared to be not unfrequent on the table land of Bahia, associ- 
ating in pairs, and never perching on the ground. 

2. Tachyphonus olivaceus. Sp. Nov. 
T. supra olivaceus, infra fulvido-albus ; vertice cinereo ; regione oculariflavd. 
Above olive ; beneath fulvous white ; crown cinereous ; region 
of the eye yellow. 

Description, — Size of T. nigerrimus ; the form of the bill is 
typical, but its size is intermediate between that bird and T. Des* 
maresti; its colour is black. Plumage above, brownish olive ; 
ears, crown of the head, and sides of the neck, dull cinereous ; 
the feathers round the eye are yellow, and the sides of the head 
obscure olive. All the under parts are fulvous white ; vent and 
flanks brownish, but the under tail covers are tinged with fulvous. 
Tail rather long, the colour brown ; but the outer webs of the fea- 
thers are olive. Tarsi pale. 

Total length 6£, bill T ^, wings 3, tail 2f , tarsi T 7 <y, 

I have ventured to describe this as a distinct species ; although, 
from its olive-coloured plumage, I entertain some doubts whether 
it may not prove to be a female, in which case the specific cha- 
racter must be altered to suit the plumage of the male. In the 
proportions of the bill and tail it does not agree with any of the 
species here described. 

This bird was originally in the collection of Mr. Hullet : IJueno* 
Ayres was given as its locality. 

3. Tachyphonus Vigorsi. Sp. Nov. 
T. violaceo-niger, cristd rubrd; scapularibtis tectricibusque inter ioribus niveis. 

Glossy black ; crest red ; scapular and under wing covers 
snowy. 

In its size and general proportions, this species resembles T. 
nigerrimus, but the bill is comparatively shorter ; and the upper 
mandible is less arched, and less elevated between the frontal 
feathers. On the crown of the head is a short narrow crest of an 


64 Mr. Swainson on the 

orange-red colour, and the scapular and inner wing covers are of 
a snowy- whiteness ; with these exceptions, the whole of the plum- 
age is deep black, richly glossed with blue. The fourth quill is 
somewhat longer than the third and fifth : the tarsi are black, and 
rather short. Inhabits Southern Brazil. Manners unknown. 

Total length 7, bill ^, wings 3|, tail 3|, tarsi f . 

I cannot designate this species (one of the most conspicuous 
in the group) by a name more distinguished than that of the 
highly-gifted ornithologist, whose essay on the " Affinities of 
Birds" has thrown a new light on this interesting department of 
nature. 

4. Tachyphonus rubescens. 

T. suprh rubro-fuscus, infrh rubescens ; crista coccineae marginibus lateralibus 
nigricanlibus ; rostro brevi, conico. 

Above brown, beneath reddish ; crest crimson, the lateral mar- 
gins blackish ; bill short, conic. 

Friogilla cristata ? Fr. spadicea, subtus rubra, vertice cristato rubro, tempo- 

ribus nigris. 
Gmelin Syst. Nat. 1. pars 2. p. 926. 
Latham Ind. Orn. 1. 434. 2. 
Moineau de Cayenne Buff. PI. Enl. 181. f. 1. 
Blackfaced Finch ? Latham, Gen. 3. 253. 3. 
Fringilla cristata. Shaw, Genl. Zool. 9, p. 440. 

Description. — Size rather smaller than that of the goldfinch; bill 
short, compressed, conic ; the margins of the upper mandible very 
slightly sinuated. The colour of the upper plumage is reddish - 
brown, excepting the rump, which is dull crimson. On the crown 
is a somewhat lengthened crest of bright crimson, margined on 
each side by a stripe of dark-brown ; all the under parts, from the 
chin to the tail covers, dark red ; wings and tarsi brown ; tail 
blackish, and nearly even ; inner wing covers white ; bill above 
dark brown ; beneath almost white ; sides of the head brown. 

Total length 5 J, bill from the rictus 3%, wings 2§, tail 2|, 
tarsi ^ 

This description has been drawn up from a specimen of the 
male bird sent to me from Rio de Janeiro. It seems to differ from 
the Moineau de Cayenne of Buffon, in some few particulars, which 


genus Tachyphonus. 65 

may probably arise from the difference of their locality. The black- 
faced finch of Pennant, said to inhabit Carolina, and the more 
northern provinces, cannot surely be the same as the Brazilian 
species. 

It is not without hesitation that I have ventured to remove this 
bird from the Fringillce of Linnaeus, and to place it in the present 
group. In so doing, I have been guided by its general habit, 
which agrees more with Tachyphonus, than with any other defined 
genus ; the bill, although short and conic, is very much com- 
pressed, while the margins are inflexed, and very slightly 
sinuated. 

5. Tachyphonus fringilloides. Sp. Nov. 

T. suprh cfnereus, infrd albem, crista coccinea, marginibus lateralibm nigris / 
rostro brevi, conico. 

Above cinereous, beneath whitish, crest crimson, the sides black, 
bill short, conic. 

This beautiful little bird is even smaller than the preceding. 
The colour of the upper mandible is brown, and that of the under 
white ; the crest is of a vivid crimson, and the sides margined by 
a stripe of deep black ; the rest of the upper plumage is cinereous- 
gray, and this colour tinges the white of the under plumage ; the 
wings are brown ; the tail black, and very slightly rounded ; 
tarsi and claws pale. 

Total length 4|, bill ■%% wings 2 T % tail 2-&, tarsi J J. 

I believe this to be a bird of rare occurrence. During a month's 
encampment on the table land of Bahia, I failed in procuring more 
than two individuals, both of which were males ; neither am I 
aware of its having been met with in any other part of Brazil. 
In the shortness and compression of the bill it agrees with T. 
rubescens; but the tail, which in that bird is nearly, if not quite, 
even, in this is more rounded ; the feathers likewise are broader. 
The margins of the bill are inflexed, but not sinuated; and the 
acute angle, which constitutes a very prominent character in the 
Fringillce, is wholly wanting in both these birds. 

Vol. XX. F 


66 Mr. Swalnson on the 

6. Tachyphonus Suchii. Sp. Nov. 

T. olivaceus, infr& palliddfulvus ; cristdjlavd; alts nigris ; remigum pogoniis 
internis basi albis. 

Olive, beneath pale fulvous, crest yellow ; wings black, the in- 
ternal base of the quills white. 

Description. — This is of an intermediate size between T. Vigor si 
and T. cristatus, but the bill is smaller and much weaker than 
that of the last-named bird, the upper mandible also is less convex 
above, and the margins, although innexed, are not at all sinuated ; 
the bristles of the rictus are stronger, and extend to half the 
length of the bill. The front and sides of the head are black ; 
and the crown is ornamented by a half- concealed crest of straw- 
coloured yellow feathers ; the ears are dusky black. The general 
colour of the upper parts of the body is obscure olive ; the wings 
are deep black ; the scapulars tinged with olive ; and the quill 
feathers, with the exception of the two first, are all marked at the 
base of the inner webs by a band of pure white. All the under 
plumage is pale fulvous, tinged with olive on the flanks, and 
verging towards white on the abdomen: the tail is black, of a 
rounded form, and the feathers rather broad ; tarsi pale. . 

Inhabits the southern parts of Brazil. My specimen was libe- 
rally communicated to me by Dr. Langsdorff. 

Total length 6§, bill T 6 ff , wings 3|-, tail ft£i tarsi ^. 

I recollect seeing this species, or one very nearly resembling it, 
among the valuable zoological collections made by Dr. Such, in 
the southern provinces of Brazil, and which have furnished mate- 
rials for some interesting and valuable papers, communicated by 
that gentleman to the scientific Journals. I therefore embrace 
this opportunity of affixing his name to a native bird of that 
country which he has so successfully explored. 

7. Tachyphonus Cristatus. 

T. niger; crisld rubrd ; mento uropygioque fulvis ; scapularibus teclricibusque 
inlcrinribus albis. 

Black, crest red ; chin and rump fulvous ; scapular and inner 
wing-covers white. 


Genus Tachyphonus. 67 

Tanagra cristata. Linn. Syst. Nat. 317. Index Orn. 

Tanagra cayennensis nigra cristata. Brisson Ornith. append, p. 65, tab. 4, f. 3. 

Hauppette." Huftbn PI. Enl. 7, fig. 2. 

Desmarest Hist. Nat. desTanagres, pi. 47. 

Crested Tanager, Lath. Gen. Synopsis 2, p. 221. 

Description. — Bill entirely black, strong, and rather dilated at 
the base ; the rictus furnished with a few weak bristles, and the 
margin of the upper mandible considerably sinuated. The crown 
of the head is covered by a conspicuous crest of bright orange-red, 
having the margins paler and more of a fulvous yellow. The ge- 
neral colour of the plumage, both above and beneath, is brownish 
black ; across the rump is a broad band of fulvous, and beneath 
the chin is a short stripe of the same colour, extending half way 
down the throat : part of the scapula, and the whole of the inner 
wing-covers, are pure white ; wings brown ; tail black, and rather 
lengthened ; tarsi brown. 

This species appears subject to some variation in the colour of 
the crest, and in the extent of the fulvous stripe on the throat. 
But as these varieties have not come under my own observation, 
I must refer the reader to the admirable work of M. Desmarest on 
this family. The above description has been taken from the male 
bird as it usually occurs in Brazil : the female I have never seen. 
I have frequently had occasion to observe, that where the same 
species is found both in Cayenne and Brazil, the specimen 
from the former country is invariably larger and more richly 
coloured : may not this be attributed to the excessive heat and hu- 
midity of that province, which may be supposed to affect the 
animal productions no less than those of the vegetable world ? 

8. Tachyphonus Desmaresti. Sp. Nov. 

T. violaceo-niger ; crUtd uropygioque fxdvis ; crisso rufo; leclricibus inferior 
ribus niveis. 

Glossy black ; crest and rump fulvous yellow, vent rufotis ; 
under wing-covers snowy. PI. Enl. 301, f. 2. 

Description. — Size of T. cristatus ; but the bill is longer, more 
slender, and more pointed ; and the upper mandible is less curved. 
The general colour of the plumage, both above and beneath, is deep 

F 2 


68 Mr. Swainson on the 

black; glossed with blue in every part but the wings and tail. 
The crown has a concealed crest of buff-coloured feathers, and on 
the rump is a broad band of the same tint. The vent and under 
part of the flanks are deep rufous ; tail-covers black ; under wing- 
covers snowy white. On closely examining the tarsi of the spe- 
cimen in my collection, (the only one I have the means of consult- 
ing,) I find they do not naturally belong to the bird. This artifice 
was formerly much resorted to by bird-stuffers, who thought it no 
sin to give new legs to a bird when its own were unserviceable. 

In the sale catalogue of Mr. Hullet's collection, this bird is 
stated to have been sent from Buenos Ayres. 

Bill T 7 ^, wings 3, tail 3. 

Naturalists have hitherto considered this as a variety of T. 
eristaiusy but even admitting that the difference in their plumage is 
not very considerable, the more lengthened, pointed, and attenuated 
form of the bill, in this bird, at once points it out as a species in- 
termediate between T. cristatus and T. tenuirostris : I therefore feel 
happy in recording it under the name of Desmaresti, as a just tri- 
bute of respect to that celebrated ornithologist, who has illustrated 
the Tanagrce of Linnaeus in one of the most splendid publications 
of the present day. 

9. Tachyphonus Tenuirostris. Sp. Nov. 

T. violaceo-niger ; scapxdaribus albis ; caudce tegminibus inferioribus mfis ; 
rostro gracilL 

Glossy blue-black ; scapulars white ; under tail-covers rufous ; 
bill slender. 

Description. — In its general proportions this is rather smaller 
than the preceding ; the bill, in particular, is much more slender, 
the culmen more arched, and the lateral margins are more than 
usually inflexed. The general colour of the whole bird is a deep 
and glossy raven black ; but the scapular, and parts of the lesser 
wing-covers, are pure white, and the under tail-covers deep rufous. 
The wings and tail agree in their structure with those of the more 
typical species. The bill and tarsi are black ; and the latter ap- 
pear rather lengthened. The dispersion of Mr. Hullet's cabinet 


Genus Tachyphonus. 69 

of ornithology, some years ago, by public sale, put me in pos- 
session of this, and several other little-known birds, from the in* 
terior of Buenos Ayres. 

Bill T 6 ff , wings, 2£, tail 2£, tarsi -&. 

There is an evident affinity between this and the two preceding 
species in their general habit, and in the disposition of their 
colours ; but the bill, which in T. cristatus is thick and compara- 
tively short, becomes more slender and attenuated in T. Desmaresti, 
and we are thus prepared for the still greater weakness of this 
organ in T. tenuirostris ; nevertheless, in all these species, the ty- 
pical characters are more or less preserved. It may be added that 
these characters of the bill can even be traced in the Tanagra 
velia, and this bird may probably connect Tachyphonus with the 
genuine Tanagers. 

There are several other South-American birds, arranged in the 
old genus Tanagra, which seem to bear an affinity to this group ; 
but as they are only known to me by the descriptions of Dr. 
Latham, or the figures of Buffon, I cannot venture to give them a 
place in the present monograph. 


Art. XL Supplement to a Paper on the Vibrations of 
Heavy Bodies, in the Fifteenth Volume of this Journal. 
By Davies Gilbert, Esq. M.P., Treas. R.S., &c. 

Having inserted in the XVth volume of the Quarterly Journal, a 
Paper on the vibration of Heavy Bodies in cycloidal and in circular 
arcs, I am now desirous of adding a supplement to the part, which 
relates to the variation of time, occasioned by different buoyancies 
of the atmosphere, as the barometer rises or falls. 

My attention was first directed to the subject by the late Doctor 
Maskelyne ; and as it appears from a very simple calculation, that 
each inch of variation in the height of the barometer must change 
the daily rate of a clock connected with a brass pendulum, about 
two-tenths of a second, in so far as buoyancy is alone concerned ; 
I constructed a table for each hour, and for every tenth of an inch. 

Having requested Mr. Pond and Doctor Brinkley to observe the 
rates of their clocks, when the barometer stood at its opposite ex- 


70 Davies Gilbert, Esq., on the 

tremes, they were so good as to do so ; and I learnt, with much 
surprise, that neither at Greenwich nor at Dublin had the expected 
variation of rate taken place. 

It has been demonstrated by Sir Isaac Newton, that small 
changes in the resistance to oscillatory bodies do not by their 
direct action cause any variation in the times of vibration, since 
the ascending and descending semivibrations compensate each 
Other ; but increased resistance reduces the arc, where the main- 
taining power is constant; and, consequently, it reduces also the 
circular excess, so that an increased resistance thus indirectly 
accelerates the time of vibration. This circumstance has been 
noticed by various writers, and had not escaped my attention; 
but the quantity seemed so very small as to be wholly evanescent, 
in comparison even with the minute change of time assignable 
to buoyancy. On submitting it, however, to calculation, the result 
proved very different. 

Let h express in barometncal inches the density of the atmo- 
sphere. 

Then since the resistance experienced in moving through any 
space, is proportionate to the space itself, to the velocity, and to 
the density of the medium : and in the cycloid, or in small circular 
arches, the space and the velocities of semivibrations are propor- 
tionate to each other : 

If R be put for the resistance, 
and z for the arc, 
R = Az 2 . 

But resistance is evidently equal to the maintaining power, con- 
sequently hz 2 is constant ; and therefore 

z 2 h s= 2hzz, or zh He 2hz, and z ie z x — - 

2/ t 

whence it appears that in different arcs the variation of the lengths, 
occasioned by a given variation of the barometer, is proportionate 
to the arcs themselves. 

Now the circular excess in any small circular arc is T ^th part of 
the. arc squared. (See page 10 of the paper referred to.) Whence 
the variation of this excess ; or the fluxion of the time (t) cor- 
responding it h h, will be 


Vibrations of Heavy Bodies, 71 


16 V. 2* J 16 h 

But the time of descent down the arc of a cycloid, or through 
any small circular arc, is inversely as the square root of the mov- 
ing force. 

Let gravity, as acting in a vacuum, be represented by unity. 

Let S = the specific gravity of the pendulum, 

s = the specific gravity of air, at the height (A) of the 
barometer. 

Then will 1 — — represent the moving force, 
S 

and t = 


v/'-i 


S 
But t, as compared with h, will be 

t = 1 L The first term 

J\- s x hVh xA~- 

v l "S x T" v s 

Is h 

of which expression, being expanded, is -r- x "g" x ~r as f. 

By making this equal to the variation in the time occasioned by 
buoyancy, 

JL X -1 X A = 1 z* X A V ** = 8 ± 
2 1 h h 

and z ss 

Then if air be taken at the specific gravity of 

JL its log 7.0819697 

828 fe 

The spec. grav. of brass 8.8, 4 its log. 0.9242793 > 9 0757 o 07 

Ar. Com S 

8 its log. . 0.9030900 

2)7.0607804 

8.5303902 

Degrees in radius 57°.2958 the log 1.7581226 

.2885128 
which gives 1°.9432, or 1° 56' 35" for the vibration on each side 


72 


Davies Gilbert, Esq., on the 


of the perpendicular, or nearly two degrees. With a mercurial 
pendulum the arc of semivibration must be 1° 31' 44", or about 
one degree and an half. 

And it is an extremely curious circumstance, that without any 
reference to the attainment of this balance between opposite disturb- 
ing causes, our best clocks should have been fortuitously made to 
vibrate very nearly in the arc, which reduces them to an equality. 

Friction is supposed to be so very small in amount, and more- 
over to possess such very trifling influence on these minute changes 
as not to require attention. 

All thermometrical changes are corrected by the ordinary com- 
pensation. Nor is it of any practical importance to estimate h t (the 
height of the barometer from whence the variation t. is to com- 
mence,) at any other standard than 30 inches, unless, indeed, the 
barometer should be placed in some very elevated situation. — When 
other tables should be constructed from the new values of t and s. 

The following table, reprinted from the former communication, 
gives the effect of buoyancy on a brass pendulum. These numbers 
multiplied by six- tenths, ( .6) become adapted to a mercurial pen- 
dulum ; and the same numbers multiplied by the following factors, 
with their signs changed, will give the effect arising from varia- 
tions of the circular excess ; for degrees, and quarters of degrees 
of semivibration. 


/ 

1 . 


. 0.265 


O / 

3 . 


. 2.38 


o > 
5 . 


. 6.62 


1 15 . 


. 0.414 


3 15 . 


. 2.80 


5 15 . 


. 7.30 


1 30 . 


. 0.596 


3 30 . 


. 3.24 


5 30 . 


. 8.01 


1 45 . 


. 0.811 


3 45 . 


. 3.72 


5 45 . 


. 8.77 


2 . 


. 1.06 


4 . 


. 4.24 


6 . 


. 9.53 


2 15 . 


. 1.34 


4 15 . 


. 4.78 


6 15 . 


. 10.34 


2 30 . 


. 1.66 


4 30 . 


. 5.36 


6 30 . 


. 11.19 


2 45 . 


. 2.00 


4 45 . 


. 5.98 


6 45 . 


. 12.07 


A Table, reprinted from the XVth vol. for correcting the time, as 
shewn by a clock, having a brass weight, or ball to its pendulum, 
for the variation of one inch in the height of the barometer. 
Arguments. — The time elapsed since the last observation of the 

barometer. 

And the present observed height — 30 inches d~ J_ the variation 
between the observations — 2 

Additive, if the sum is Plus. — Subtractive, if it is Minus. 


Vibrations of Heavy Bodies, 73 


h 123456789- 

Tb~ TIT T~5* To Tb~ To" To Tb" To s 

1 . . 00 00 00 00 01 01 01 01 01 01 

2 . . 00 00 01 01 01 01 01 01 01 02 

3 . . 00 01 01 01 01 02 02 02 02 03 

4 . . 00 01 01 01 02 02 02 03 03 03 

5 . . 00 01 01 02 02 03 03 03 04 04 

6 . . 01 01 02 02 03 03 04 04 05 05 

7 . . 01 01 02 02 03 04 04 05 05 06 

8 . . 01 01 02 03 03 04 05 05 06 07 

9 . . 01 02 02 03 04 05 05 06 07 08 

10 . . 01 02 03 03 04 05 06 07 08 08 

11 . . 01 02 03 04 05 06 06 07 08 09 


12 . 


. 01 


02 


03 


04 


05 


06 


07 


OS 


09 


10 


13 . 


. 01 


02 


03 


04 


05 


07 


OS 


09 


10 


11 


14 . 


. 01 


02 


04 


05 


06 


07 


OS 


09 


10 


12 


15 . 


. 01 


03 


04 


05 


06 


08 


09 


10 


11 


13 


16 . 


. 01 


03 


04 


05 


07 


OS 


09 


11 


12 


13 


17 . 


. 01 


03 


04 


06 


07 


09 


10 


11 


13 


14 


18 . 


. 02 


03 


05 


06 


OS 


09 


11 


12 


14 


15 


19 . 


. 02 


03 


05 


06 


08 


10 


11 


13 


14 


16 


20 . 


. 02 


03 


05 


07 


08 


10 


12 


13 


16 


17 


21 . 


. 02 


04 


05 


07 


09 


11 


12 


14 


16 


18 


22 . 


. 02 


04 


06 


07 


09 


11 


13 


15 


17 


18 


23 . 


. 02 


04 


06 


OS 


09 


12 


13 


15 


17 


19 


24 . 


. 02 


04 


06 


08 


10 


12 


14 


16 


IS 


20 


In the case of a mercurial pendulum, these quantities must be 
reduced to three-fifths ( .6) of their magnitudes in the table. 


74 Mr. Daniell's Correction of an Error 

Art. XII. Correction of an Error in the (i Meteorological 
Essays:' By J. F. Daniell, F.R.S. 

I am indebted to an anonymous critic in the Dublin Philosophical 
Journal^ no less for pointing out a mistake into which I have care- 
lessly fallen in my Meteorological Essays, than for the flattering 
terms in which he has spoken of the work in general. The mistake 
occurs at p. 178, $• seq. in the table for finding the specific gravi- 
ties of various mixtures of air and aqueous vapour. The table con- 
sists of five columns ; — the first contains the degrees of temperature 
from 0° to 90° ; the second the alterations of volume due to each 
degree of heat ; the third the increments of volume from the addi- 
tion of vapour of any given temperature ; the fourth the increase of 
density from the weight of the same vapour ; and the fifth the cor- 
rect specific gravity of saturated air. In calculating the last I have 
deducted or added the increase of volume from unity, instead of cal- 
culating the specific gravity in inverse proportion to such alteration. 
The mistake is so very obvious, that I could not have extended the 
table much further without having been aware of its commission : 
but withinits actual limits it is of much less amount than might have 
been at first supposed. The facility with which errors of this de- 
scription slip from the pen cannot be better illustrated than by an 
oversight of an analogous nature of my Reviewer himself, who 
observes, upon the formula for calculating the expansion of gas 
from moisture, " If the volume of the dry gas = 1, and the height 
of the barometer and the elasticity of steam be represented 
respectively by p and/, when the gas is saturated, its volume will 

have become r= _ E — " Now if this were the case, when the 

p-f 

height of the barometer is 30, and the elasticity of the vapour is 

30 

30 also, the volume becomes . , which is clearly impos- 

30-30 

sible ; the formula upon which my calculation is founded is 

P—L ; which gives, upon the same supposition, — X , or double 

p 30 

the volume. 

The follow ng corrected table should be substituted for the one 

already alluded to. 


in the " Meteorological Essays" 


75 


1 


fcj 


CO 


© 

«5 


tj 


© 


CM 

00 


© 

to 


8 


«3 


— 


00 


CM 


© 


1 


00 


«0 


CO 


CO 


CM 


CM 


CM 


8 


— 


~ 


1-4 


id 


P! 


© 


© 


© 


© 


o 


© 


© 


© 


© 


© 


© 


o 


*% 


|i 


1H 


^ 


© 


oo 


to 


*# 


CM 


CM 


'"f 


N 


en 


— 


oo 


»o 


s 


if? 


*C 


to 


to 


N 


00 


OJ 


© 


1*4 


CM 


CO 


»o 


to 


N 


00 


£ II 


CM 


CM 


CM 


CM 


CM 


CM 


CO 


CO 


CO 


CO 


CO 


co 


CO 


CO 


o 


o 


a 


© 


© 


© 


© 


© 


o 


o 


© 


© 


o 


§ 


§ £o 


^N 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


- 1 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


ag 


*f 


N 


© 


co 


N 


© 


N 


*> 


N 


N 


N 


N 


N 


** 


III 


00 


CJ 


— 


CM 


CO 


«5 


to 


00 


© 


CM 


Tf 


to 


00 


© 


CO 


CO 


^ 


Tf* 


Tf* 


r** 


■<* 


m 


*o 


«5 


«3 


»o 


^i 


to 


o 


o 


o 


o 


r> 


O 


o 


C5 


© 


© 


r> 


o 


o 


1 


ft 


c 

+ 


© 


© 
+ 


© 
+ 


© 
+ 


© 
+ 


o 

+ 


© 


© 


© 


© 


© 


© 


tj^ 


ST *o 
^00 


cr> 


w* 


CO 


-* 


to 


Q0 


o 


— < 


CO 


«<* 


to 


00 


o> 


*» d 


V 


«* 


CO 


CM 


i— • 


© 


o 


O 


00 


N 


to 


»c 


^ 


•f 


ijj 


N 


W5 


CO 


— 


0> 


^ 


»o 


Q>t 


o 


00 


to 


Tf 


CM 


© 


co 


CO 


CO 


CO 


fM 


(M 


CM 


ot 


CM 


— 


— 


— 


— < 


fH 


PI 


© 


O 
1 


© 

i 


© 
\ 


© 
1 


© 
l' 


© 
1 


© 

1 


© 
l' 


© 

1 


© 

1 


© 

r 


© 

1* 


© 


11 


i 


-* 


>o 


to 


N 


00 


OJ 


© 


_ 


■->.' 


«0 


•* 


»o 


to 


N 


.H . 


— 


CM 


CM 


CM 


CM 


CM 


CM 


(M 


CM 


o 


12 


CO 


~ 


*o 


— 


fe 


CO 


o 


© 


N 


■5 


CO 


00 


W5 


co 


—i 


00 


to 


•<* 


t3> 


«^ 


N 


to 


to 


to 


to 


»o 


>o 


■B 


«5 


■** 


fli 


Tf* 


* 


CO 


© 


© 


© 


© 


o 


© 


© 


© 


© 


© 


© 


© 


© 


© 


4^Q 


"** . 


f 1 


CO 


o> 


to 


CM 


o 


m 


— 


N 


^» 


© 


to 


^> 


"<J» 


CO 


M 


■ 


«5 


to 


N 


N 


00 


Oi 


OJ 


© 


— 


CM 


co 


"* 


r—> 


*-< 


^N 


r~* 


1— 1 


t~* 


^H 


1—4 


CM 


CM 


CM 


CM 


fM 


CM 


© 


o 


© 


© 


© 


© 


o 


© 


© 


O 


© 


© 


© 


o 


© 


© 

+ 


© 

+ 


© 
+ 


© 


© 
+ 


© 

+ 


o 

+ 


© 


© 
+ 


© 


o 

+ 


© 


© 


%b 


to 


N 


K 


N 


N 


N 


N 


N 


N 


N 


N 


CO 


N 


© 


III 


cm 


CO 


M< 


«3 


to 


N 


00 


it 


CM 


CM 


CM 


CM 


CM 


CM 


CM 


CM 


CO 


CO 


CO 


CO 


CO 


co 


o 


© 


© 


© 


© 


© 


© 


O 


© 


o 


© 


© 


O 


© 


•KB •**> 


Ha 


© 


© 


© 


© 


© 


© 


O 


© 


© 


© 


© 


© 


© 


© 


bjno 


so 


< & 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


^ 


**> 


to 


an 


OJ 


— 


eo 


-* 


to 


00 


OS 


— 


CO 


*!» 


to 


00 


1 J 


CO 


«5 


w 


<P 


CO 


CM 


© 


05 


OJ 


00 


N 


to 


»o 


III 


to 


■>* 


CM 


© 


on 


to 


s 


CM 


OJ 


N 


»o 


CO 


— 


CJ 


to 


to 


to 


to 


»o 


W5 


p 


o 


-* 


««* 


Tf 


•* 


■* 


CO 


in 
< ^ 


© 

1 


© 

i 


© 


© 

1 


© 
\ 


© 
f 


© 

\ 


© 

1 


© 

1 


© 

1 


© 

1 


O 
I' 


© 

i 


o 

1* 


j 


< 


i 


© 


ff 


(M 


CO 


««f 


«3 


to 


N 


00 


o> 


© 


l-l 


CM 


CO 


H 


H 


76 


Mr, Darnell's Correction of an Error 


o 


© 


© 


on 


N 


N 


co 


fc 


CO 


CO 


wo 


wo 


wo 


W0 


W0 CO 


sal 

PI 


GO 


© 


N 


wo 


00 


r— 1 


© 


WO 


CO 


i— t 


© 


N 


W0 


00 l-H 


N 


CO 


CO 


CO 


CO 


CO 


wo 


W0 


WO 


wo 


wo 


■* 


rf< 


^ 


^ ^ 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© © 


>• 


N 


© 


CO 


CO 


© 


CO 


© 


•* 


CO 


CO 


N 


N 


N 


m* 00 


Id 


N 


© 


Of 


rp 


CO 


00 


© 


co 


CO 


© 


GO 


US 


on 


W0 CO 


CO 


CO 


N 


N 


*s. 


K 


on 


on 


CO 


00 


© 


© 


© 


© 


© © 


o 


o 


© 


© 


© 


© 


o 


© 


© 


© 


o 


© 


© 


1— 1 — 


O 


O 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© © 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ + 


<# 


tP 


# 


^ 


■* 


■rap 


T? 


© 


CO 


© 


*p 


CO 


© 


rp 


«? © 


° B* 


© 


00 


N 


F— 1 


W0 


© 


CO 


CO 


GO 


on 


CO 


oo 


"* 


© 


wo *-. 


e k o 
2 E & 


o 


CO 


w 


GO 


oo 


00 


Tj< 


"^ 


wo 


W0 


CO 


CO 


N 00 


g s * 


o 


o 


© 


© 


© 


© 


© 


o 


© 


© 


© 


© 


© 


© 


© © 


£>§• 


< l\ 


+ 


+ 


.+ 


4- 


.+ 


+ 


-1- 


+ 


rf 


+ 


+ 


+ 


+ 


+ 


+ + 


© 


on 


CO 


m 


co 


— ■ 


© 


on 


CO 


rP 


oo 


1— 1 


© 


CO 


CO rfr 


"8 j 


© 


© 


1— I 


co 


00 


** 


*• 


*o 


CO 


N 


00 


© 


© 


© 


^ GO 


Sl f J 


R 


N 


© 


i— i 


oo 


wo 


<^ 


© 


p— < 


CO 


W0 


N 


© 


GO 


TjH CO 


5 is 


GQ 


o> 


oo 


CO 


00 


CO 


00 


CO 


<*P 


rf* 


Tp 


tH 


"+ 


W0 


W5 W0 


Ijsa 


o 


O 


o 


© 


© 


© 


© 


© 


© 


O 


© 


© 


© 


© 


© © 


3 * 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


ff 


+ 


+ 


+ + 


D. 
| 


If 


wo 


CO 


N 


on 


© 


© 


1— 1 


GO 


CO 


*T> 


W0 


CO 


K 


oo © 


^p 


m 


Pi 


S 


■* 


m 


m 


*3 


wo 


wo 


wo 


wo 


wo 


WO 


wo »o 


«£1 


1— 1 


N 


wo 


co 


H 


CO 


** 


— 


© 


N 


wo 


GO 


© 


00 


CO 


TT< 


GO 


© 


on 


CO TJH 


© 


O 


© 


© 


© 


© 


© 


© 


00 


on 


00 


CO 


00 


N 


N N 


o 


o 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© © 


PI 


1-^ 


1— 1 


i— i 


© 


m 


00 


© 


■«£ 


^H 


CO 


CO 


on 


CO 


© 


Tf- 


© 


"# 


N © 


V* 


© 


1—i 


oo 


CO 


W0 


i^ 


00 


© 


1— 1 


oo 


Tf 


<o 


on 


© 


G) «0 


00 


-* 


•^ 


*+ 


^f< 


tP 


Tf* 


WO 


W0 


W0 


wo 


WO 


wo 


CO 


CO CO 


IP 

las 


o 


o 


© 


© 


© 


© 


© 


© 


© 


© 


o 


© 


© 


© 


© © 


o 


o 


o 


© 


© 


© 


© 


© 


© 


© 


o 


© 


© 


© 


© © 


M «§ 


+ 


+ 


+ 


+ 


+ 


K 


N 


K 


•* 


SS 


N 


CO 


o 


K 


*p 


N 


*P 


o g 


GO 


rf» 


CO 


© 


r— 1 


III 


CO 


CO 


co 


CO 


N 


N 


N 


00 


CO 


00 


00 


© 


a 


© 


© © 


o 


O 


© 


o 


© 


© 


© 


© 


o 


© 


© 


o 


© 


00 


p- 1 i— i 


PS 


o 


O 


© 


© 


o 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© © 


< * 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ + 


CO 


*+ 


CO 


00 


•© 


on 


co 


rP 


00 


w < 


© 


on 


CO 


^p 


00 ~H 


o „• 


00 


GO 


1— 1 


© 


o 


© 


■-* 


CO 


00 


Tp 


Tf< 


wo 


CO 


N 


00 © 


III 


00 


CO 


H* 


CO 


© 


CO 


«* 


co 


00 


o 


ftO 


rp 


CO 


on 


© GO 


o 


O 


o 


© 


© 


o 


O 


© 


© 


l—H 


•— ( 


GO GO 


Hi 


o 


O 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© 


© © 


1 


1 


1 


1 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ + 


i 


00 


© 


© 


P-H 


CM 


CO 


■«J» 


WO 


CO 


N 


on 


© 


© 


M 


GO 00 


GO 


00 


CO 


oo 


oo 


ill the " Meteorological Essays." 


77 


112 


N 


N 


CO 


co »o 


CO 


CO 


en 


l«H 


0) 


«♦ 


CO 


o 


l«H 


CM 


cfci-t 


GO 


CO 


rp 


CO 


r- 1 


o 


N 


»0 


co 


PH 


en 


CO 


CO 


Tp 


CM 


m 


O 


o 


O 


o 


o 


C75 


en 


en 


en 


en 


CO 


CO 


CO 


CO 


CO 


©> 


en 


O 


en 


C> 


CO 


CO 


CO 


CO 


CO 


GO 


CO 


CO 


CO 


GO 


o 


pii 


CO 


CO 


o 


© 


o 


co 


N 


CO 


l-H 


CO 


en 


CO 


CO 


"8 2 


^i 


CO 


PH 


N 


CO 


CI 


*o 


»— 1 


t» 


«* 


f-H 


CO 


■^ 


^* 


CO 


!# 


co 


00 


Si 


o» 


8 


r> 


(N 


Oi 


CO 


Tf* 


rt< 


"3 


CO 


CO 


l-H 


l-H 


t-i 


CM 


CM 


r.v 


O) 


O) 


O) 


Gi 


CM 


CM 


CM 


i«i 


o 


o 


c 


O 


o 


c 


o 


o 


o 


o 


o 


© 


© 


© 


© 


+ 


+ 


t 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


o 


s 


CO 


N 


CO 


CO 


CO 


CO 


CO 


CO 


CO 


CO 


CO 


CO 


CO 


jii 


CM 


CM 


CM 


CO 


<* 


«5 


N 


en 


rt 


T* 


N 


8 


CO 


CO 


i— < 


©1 


CO 


-«* 


»o 


CO 


N 


CO 


en 


— 


w 


CO 


CO 


N 


CO 


co 


CO 


co 


co 


CO 


CO 


CO 


CO 


f 


•^ 


•* 


tJi 


tP 


T** 


i%> 


o 


o 


o 


o 


o 


o 


o 


o 


o 


o 


o 


© 


© 


© 


o 


h 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


CO 


■* 


CO 


l-H 


Oi 


CO 


co 


^ 


co 


' m 


en 


CO 


CO 


•* 


60 


* 4 


CO 


N 


CO 


C5 


0> 


o 


©} 


co 


•* 


t* 


»o 


CO 


N 


CO 


IM 


i-i 


CO 


*0 


N 


OS 


CM 


tp 


CO 


CO 


o 


O) 


•^ 


CO 


CO 


o 


en 


en 


OJ 


OS 


05 


o 


o 


c 


o 


r— 1 


l-H 


PH 


— 


<M 


PI 


© 


o 


o 


o 


o 


« 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


-t- 


+ 


+ 


+ 


+ 


f 


+ 


§ 


CO 


N 


CO 


r. 


o 


l-H 


CM 


CO 


** 


»n 


co 


N 


CO 


en 


O 


*> 


i> 


i> 


N 


CO 


CO 


CO 


GO 


CO 


CO 


CO 


co 


GO 


CO 


en 


8w. j( 


CO 


CO 


co 


N 


N 


"5 


OJ 


N 


»o 


CO 


r— 


o» 


N 


V5 


rf< 


t>» 


8 


CO 


CO 


«>* 


CM 


O 


CO 


co 


CO 


CO 


CO 


CM 


CM 


O) 


GM 


GV 


— 


l-H 


i— * 


^ 


l-H 


en 


Ci 


en 


o 


en 


OS 


en 


en 


en 


en 


en 


en 


en 


en 


en 


en 


-<£ 


CO 


CO 


N 


CO 


»o 


^ 


c» 


>o 


N 


CO 


»— » 


GO 


GO 


9> 


CM 


* 2 


l-H 


^ 


N 


>o 


en 


CO 


N 


i—i 


«3 


O 


»o 


en 


• 


en 


*o 


2 


1— « 


1-4 


CM 


cm 


CM 


CO 


CO 


rf 


rp 


*o 


»o 


*o 


CO 


CO 


l> 


1 1 


o 


© 


o 


O 


o 


o 


o 


o 


o 


O 


o 


o 


© 


© 


© 


© 


+ 


+ 


+ 


+ 


+ 


+ 


y 4 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


+ 


N 


CO 


o 


o 


o 


o 


o 


o 


N 


-tf 


N 


^p 


© 


© 


CO 


© 


III 


CO 


CM 


CO 


*o 


cm 


Oi 


CO 


CO 


O 


CO 


*o 


"^ 


CO 


CM 


<M 


CO 


en 


en 


o 


r— 


© 


©I 


CM 


CM 


(N 


(N 


CM 


o» 


ot 


CM 


CM 


t» 


CM 


CO 


¥i 


o 

+ 


o 

+ 


O 
+ 


o 

+ 


© 

+ 


o 

± 


o 

+ 


o 

+ 


O 
+ 


o 

+ 


O 
+ 


o 

+ 


O 
+ 


© 

+ 


O 
± 


© 


CO 


l-H 


en 


CO 


CO 


*p 


CO 


~-t 


en 


CO 


CO 


"f* 


CO 


^, 


o> 


CO 


O w 


CO 


Tp 


*# 


*0 


CO 


N 


CO 


en 


en 


o 


^ 


o* 


CO 


^p 


"* 


*i 


CO 


O 


CM 


^f 


CO 


CO 


o 


GVJ 


•* 


N 


en 


— 


eo 


>o 


N 


en 


*o 


CO 


CO 


CO 


CO 


CO 


s 


N 


N 


N 


N 


CO 


GO 


GO 


CO 


CO 


o 

+ 


C 
+ 


o 

+ 


O 
+ 


o 

+ 


o 

+ 


o 

+ 


O 
+ 


O 


o 

+ 


O 


© 

+ 


O 
+ 


© 
+ 


© 

+ 


© 
+ 


i 


o 

CO 


f-4 
CO 


©J 


CO 


CO 


CO 


CO 
CO 


co 


CO 
CO 


en 

co 


© 


i-H 

N 


s 


CO 


N 


«3 


CO 


CO 


78 Correction in the Meteorological Essays. 

To find the specific gravity of any mixture of air and aqueous 
vapour by means of this table, we must proceed as follows : — 
Note the temperature and the point of condensation by the hy- 
grometer ; if they coincide, that is to say, if the air be in a state 
of saturation, we shall find the specific gravity required in the 
fifth column opposite to the proper degree of heat in the first 
column. If the point of condensation be below the temperature, 
we must look for the amount of the alteration of volume due to 
the heat in the second column, and for the expansion due to the 
vapour in the third column. Add these together, if they have 
like signs ; or subtract one from the other if they have different 
signs. As the volume corrected by this quantity is to the ori- 
ginal volume, so is the standard specific gravity to the specific 
gravity, as affected by the expansion or contraction. To this 
must be added the increase of weight due to the vapour in the 
fourth column, and the result will be the correct specific gravity 
sought. 

For example : — If we wish to know the specific gravity of a 
mixture of air and vapour of the temperature of 60°, and of 
which the dew-point is 40° ; we find in the second column op* 
posite to 60° the number +05833, and in the third column op* 
posite to 40° we have + .00934 : the sum of which is + .06767 ; 
therefore 

1.06767 : l :: i : 9366s. 

In the fourth column opposite to 40° we find +.00580, and 
.93668 + .00580 = .94248 ; 
which is the correct specific gravity under the assumed circum- 
stances. 


Art. XIII. On the Barometer- By J. F. Daniell, P.R.S. 

The following paper requires a few words of preface. It contains, 
as far as I am able to recollect, the substance of a communication 
which I had the honour to make to the Royal Society, in the 
month of November last, before the commencement of their last 


Mr. Daniell on the Barometer. 79 

session. As, with a former paper upon the same subject, a mis- 
take had arisen, as I was informed, from my not having expressed 
a desire to have it read, the consequence of which was that it 
was not read, I took the precaution of placing the present manu- 
script in the hands of the President, with a due notification that 
it was presented for the purpose of being read at the meeting of 
the Society. I went, immediately afterwards, upon the Continent ; 
where I was detained several months. Upon my return, in June, 
I found that the first part of the Philosophical Transactions for the 
year had been published, and that it contained no notice of my 
paper : neither could I find that any communication had been sent 
to me of its destination. I was naturally anxious to obtain some 
intelligence respecting it, and addressed a note upon the subject 
to the President ; to which he returned me the following reply : 

Dear Sir, 26, Park-street , June 5. 

Your paper was read to the Royal Society many 
months ago *, and has been before the council. There was but one 
opinion expressed as to the ingenuity of the method of preventing 
the introduction of air, supposing the cause that which you have 
assigned. The existence of this cause for the appearance of elas- 
tic matter in barometer tubes, was not considered, however, as 
proved by the experiments you have detailed, and it was therefore 
agreed by the council to wait for your return, in hopes that you 
might be able to give them some new details or elucidations from 
the researches which you stated were in progress. 
I am, dear Sir, 

Very sincerely your's, 

H. Davy. 

I immediately returned the following answer, being anxious to 
publish the paper in the ensuing Number of this Journal ; but not 
acquiescing sufficiently in the reasons assigned by Sir H. Davy to 
withdraw the paper from the judgment to which I had submitted it. 

* It was read, I am informed, on the 20th January, and several papers which 
were delivered in after its communication were read before it. 


80 Mr. Daniell on the Barometer. 

My dear Sir, 

I have no new details or elucidations to communicate to the 
Royal Society. I shall therefore be much obliged to you to have 
my paper again brought before the council for their final deter- 
mination ; unless indeed I am to understand that their determina- 
tion has been already expressed. 

I have the honour to be, dear Sir, 
Very truly your's, 
To Sir H. Davy, Bart., J. F. Daniell. 

President of the Royal Society, §*c. 

In consequence of this, the paper was again laid before the 
council, just before the recess ; when, on account of a division of 
opinion, their determination was postponed to next year. A mem- 
ber of the council then asked leave to withdraw the paper, in order 
to allow of its publication elsewhere, and stated that I had neg- 
lected to preserve a copy of the manuscript. The President, I 
am told, objected to this, and laid down the law, that the paper 
having been once taken into consideration by the council, could 
not be withdrawn. To make sure that no formality was neg- 
lected, I immediately addressed the following note to the Pre- 
sident : 

My dear Sir, Gower-street, 25th June, 1825. 

Understanding that the decision upon my paper is post- 
poned to next year, I beg permission to withdraw it. 
I remain, dear Sir, 

Your's faithfully, 
To Sir H. Davy, Bart., J. F. Daniell. 

President of the Royal Society, fyc. 

To this application I never received any answer. This is a 
brief statement of facts, upon which I shall abstain from making 
any comment. Twice before I have experienced similar treatment 
from the council of the Royal Society, and twice before I have 
appealed to the scientific public with success. I shall now endea- 


Mr. Daniell on the Barometer. 81 

vour, from memory and such rough notes as I have preserved, to 
recompose the paper, with a full conviction that the facts narrated 
are of sufficient importance to call for immediate publication, and 
satisfied, by the opinion of those who are well qualified to judge, 
that there is sufficient proof of their existence to satisfy all im- 
partial minds that the subject is well worthy of that further inves- 
tigation which it was my purpose to propose to the Royal Society. 
A new law has now been promulgated by the President of the 
Society, and every thing henceforward published in the Philoso* 
pkical Transactions must be considered as proved. The council 
will doubtless immediately drop the notice which has always 
hitherto been published in the preface to the volumes, that " they 
do not pretend to answer for the certainty of the facts or pro- 
priety of the reasonings contained in the several papers published* 
which must still rest upon the credit or judgment of their respec- 
tive authors ;" and they will, of course, be careful that this law 
is administered with impartiality. In such a regulation I, as an 
humble individual, cannot but acquiesce ; but, with many others 
I imagine, I shall always be found to resist the curtailment of the 
hitherto-acknowledged right of an author to withdraw a paper» 
any time previous to the decision of the council upon its publica- 
tion. 

In the year 1823 I presented to the Royal Society a paper upon 
the Construction of the Barometer, the substance of which I af- 
terwards published in my volume of Essays, the original paper 
having been committed to the archives of that learned body. I 
therein stated my reasons for differing from the high authority of 
the President, upon the cause of the existence of elastic matter in 
barometer tubes, suggested by him in a paper upon " the electrical 
phenomena exhibited in vacuo," and published in the Philosophi- 
cal Transactions for the year 1822. Sign. Bellani also arrived at 
the same conclusion as myself, from a series of experiments which 
he undertook, expressly to determine whether the air or vapour, 
the last portions of which are found to remain so obstinately in 
barometers and thermometers, is introduced with the mercury, or 
is a portion of that which originally occupied the tube before the 

Vol. XX. G 


82 Mr. Daniell on the Barometer, 

introduction of the metal. The conclusion he comes to is, that it is 
always a portion of that which previously adhered to the glass, and 
tfiat mercury is utterly incapable of absorbing either air or moisture. 
One of his experiments is so simple, and at the same time so con- 
clusive, that I cannot refrain from giving a short account of it. 
He filled a barometer tube, and boiled it very carefully, and then 
prepared a funnel made of a small capillary tube, which reached 
through the mercury in the barometer-tube, to the closed end, and 
was enlarged at the top. When introduced, it had been recently 
made, and perfectly dry. Some mercury was then prepared by agi- 
tating it in a bottle with water and air, and dried by means of fil- 
tering paper, and afterwards passing it through paper cones, three 
or four times, into dry vessels. A little of this mercury was poured 
into the funnel-tube, and the air extracted by means of a fine 
wire, so that the column was continuous. So much of this pre- 
pared mercury was then poured in as fully to displace the mer- 
cury which had been boiled in the tube. The barometer was 
found to stand exactly at the same height as before in the same 
circumstances ; and, when the mercury was heated, none of those 
bubbles appeared which arose on the first boiling *. 

Still further to illustrate this subject, which I thought of the 
highest importance, and to ascertain the difference of capillary 
action in boiled and unboiled barometer-tubes, I undertook the 
following experiments. The apparatus, which I made use of, con- 
sisted of an upright pillar of brass, standing upon a mahogany 
foot, upon which two horizontal arms of unequal lengths were 
made to slide; at the extremity of each of these a steel needle, 
with a fine point, was fixed perpendicularly downwards. These 
points could be adjusted to the same plane, or their relative dis- 
tance be measured, by means of a nut and screw upon the pillar, 
which carried a nonius ; and the slightest contact of these points 
with the clean surface of a basin of mercury was instantly per- 
ceptible. I satisfied myself, by repeated trials, that the adjust- 
ment might be depended upon to the one-thousandth part of an 

* Giornale de Fisica, Vol. vi. p. 20, or see Royal Institution Journal, Vol. 
iv. p. 371 


Mr. Daniell on the Barometer. 83 

inch. I made a contrivance to hold a glass tube perpendicularly 
immersed in a basin filled with mercury ; and when one of the 
steel points was made to touch the surface of the fluid in the tube, 
and the other the surface in the basin, the depression of the for- 
mer was accurately measured by the nonius. In this manner I 
determined the capillary action of several tubes, varying in their 
diameters from one to six-tenths of an inch. The results agreed 
as nearly as possible with Dr. Young's table, calculated from the 
experiments of Mr. Cavendish. The end of the tubes, opposite to 
those at which the measures had been taken, were then hermetically 
sealed, in such a manner as to be readily reopened under mercury : 
they were immediately filled with mercury, and carefully boiled. 
I expected to be able to ascertain the differences of depression by 
opening them in the basin of mercury, and proceeding as before. 
The experiment was performed as soon after the operation of boil- 
ing, as the mercury in the tube had cooled down to the tempera- 
ture of that in the basin. At first the attraction between the mer- 
cury and the glass appeared to be perfect, and no depression could 
be perceived. When, however, the tubes were left some time 
exposed, either before or after they were opened, the air and mois- 
ture insinuated themselves between the metal and the glass, and 
an immediate depression was the consequence. This depression 
increased gradually, till at length it became fixed at the exact 
point of that of the unboiled tube. The progress of this effect 
was easily perceptible with a magnifying glass, and was rendered 
still more visible fby heating the tube, when air-bubbles were 
immediately detached. This is obviously the same effect as that 
described by Sir H. Davy in his paper before alluded to, in which 
he says that, ** on keeping the stop-cock of one of the tubes, used 
in the experiment on the mercurial vacuum, open for some hours, 
it was found that the lower stratum of mercury had imbibed air, 
for when heated in vacuo it emitted it distinctly from a space of 
a quarter of an inch of the column ; smaller quantities were dis- 
engaged from the next part of the column, and its production 
ceased at about an inch high in the tube." Now, I believe that 
I should not be too presumptuous if, stopping here, I were to 

Q2 


84 Mr. Daniell on the Barometer. 

maintain that my experiment presented absolute proof that the 
air had insinuated itself between the mercury and the tube, and 
shewed that there was no " reason to believe that this air existed 
in mercury in the same invisible state as in water, that is, distri- 
buted through its pores." For, if the latter had been the case, 
the mercury, which contained no air after being boiled, would, 
from its greater density, have sunk in the tube, when surrounded 
by mercury which had not been boiled, and would have risen 
gradually as it became saturated with air. I am justified in draw- 
ing the conclusion from the contrary effect, that the air had insi- 
nuated itself between the metal and the tube, for the capillary 
depression is known to be in inverse proportion to the affinity 
of the fluid for the containing tube, and nothing could have af- 
fected that affinity in the case before us, but the gradual interposi- 
tion of a thin stratum of air and moisture. 

Having thus traced and measured the progress of the air down 
the sides of small tubes filled with mercury, and boiled with the 
greatest care, I was naturally led to suspect that the same action 
might take place in barometers, to their gradual deterioration. I 
soon saw reason to conclude that such a process actually was go- 
ing on in the most carefully constructed instruments, and that, in 
time, air would thus insinuate itself into the best Torricellian va- 
cuum. In the paper upon the construction of the barometer, to 
which I have before alluded, I gave all the particulars of the 
making of two barometers, in which every precaution was used 
to dispel every particle of air. One of these was of very large 
dimensions, and was fixed up in the apartments of the Royal So- 
ciety, under the superintendence of the Meteorological Committee. 
The other was of the mountain construction, and intended for my 
own use. The agreement between these two instruments, when 
all corrections were made for the differences in their sizes and 
forms, was very perfect, and proved that the care which had been 
bestowed upon them had not been thrown away. In the latter, 
however, I lately remarked that a small quantity of air had as- 
cended into the vacuum, I could not discover any way in which 
this could have obtained admission ; but, attributing it to acci- 


Mr. Daniell on the Barometer. 85 

dent, I laid it aside, and thought no more of it till the present 
experiments recalled it to my recollection. By a singular coinci- 
dence I was, about this time, informed that the barometer of the 
Royal Society had assumed a very remarkable appearance, and 
that the mercurial column, which was originally perfectly bright 
and compact, now seemed dull and speckled. I immediately pro- 
ceeded to examine it carefully, and I at once perceived that it was 
copiously studded with minute air-bubbles. As far as the mer- 
cury was exposed to view, the specks could be traced decreasing 
in size, from the upper to the lower part. The manner in which 
this instrument is fixed rendered it impossible to suspect that this 
air could have obtained admission by any accident ; for, unlike 
the mountain barometer, the column of metal is exposed to no 
oscillations but such as arise from differences of atmospheric 
pressure. I was myself quite satisfied, and those who have read 
the account of the precautions taken in filling the tube will also, 
I think, be satisfied, that this air was not left at its original 
construction. I now leave it to the candid to judge, whether 
" the cause which I have assigned for the appearance of this 
elastic matter in barometer tubes has not already been proved 
by the experiments which I have detailed." 

While I was occupied with these considerations, and suf- 
ficiently vexed to find that all my care had been thrown away to 
prevent my adopting that opinion without very strong grounds, 
it occurred to me that I had, in the course of my experience, 
observed a phenomenon, which was calculated to throw some 
light upon the present question ; namely, that gases were more 
readily preserved from mixture with atmospheric air over water 
than over mercury. I was unable to refer to any notes of expe- 
riments to confirm this suspicion, but I proposed the question to 
Mr. Faraday, who, I made no doubt, from his great accuracy 
and experience, must have made the observation, if it were 
founded in fact. Without at the time having any knowledge of the 
ulterior object which I had in view, heat once answered me, that 
mercury, he believed, would not confine gases for a long pe- 
riod so well as water ; and he thought, that by referring to his 
note-book, he could furnish me with the particulars of a case in 


86 Mr. Daniell on the Barometer. 

point. He accordingly did me the favour to extract the following 
particulars : — 

In June, 1823, he made a 'mixture of one volume of oxygen 
and two volumes of hydrogen ; with this he filled five dry bottles 
over mercury, and also four bottles over water. He left the 
glasses inverted over mercury and water, placing three mercury 
and two water bottles in the windows, so as to receive the sun's 
rays and day-light ; and two mercury and two water bottles he 
placed in a dark place. In July, 1824, he examined the bottles; 
the water bottle in the light contained hydrogen and some 
common air, and there was no alteration of volume ; the 
mercury bottle in light contained common air only. The water 
bottles in the dark place showed no alteration of volume, and 
the air contained in them proved to be the original mixture ; the 
mercury bottles in the same situation contained nothing but com- 
mon air. 

Now, if I had not known, from the authority of the President, 
that the Council of the Royal Society did not think this sufficient 
proof, I should very confidently have concluded from these facts, 
that a fluid which has attraction enough for glass, to enable it to 
wet4ts surface, effectually prevents the passage of gases into or 
out of vessels of that substance ; while a fluid which does not 
wet the surface permits their slow penetration. I should, more- 
over, have ventured to affirm, that the case of the confined air 
is exactly analogous to that of the barometer ; for its escape and 
the admission of the atmospheric air can only be in virtue of the 
law discovered by Mr. Dalton, that the gases are as vacua to one 
another. The inference is also pretty strong, that the filtration 
takes place along the surface of the glass, and not through the 
pores of the fluid. 

It has been attempted, I understand, to contravert this conclu- 
sion, by the observation that gases have been preserved a consi- 
derable time by mercury ; but when it is considered that the 
slightest film of moisture, or any foulness of the mercury, will 
form a connexion between the metal and the glass, the objec- 
tion can be of no avail, unless these circumstances have been at- 
tended to. To ensure the maximum of the effect which I have 


Mr. Daniell on the Barometer. 87 

been describing, it is necessary that both glass and mercury 
should be in the driest and cleanest possible state ; that is to say, 
exactly in the state in which they exist in a well made baro- 
meter. 

That another attempt has been made at explanation I can 
scarcely credit ; namely, that some facetious person had played 
Mr. Faraday a trick. The particulars of the case disprove the 
possibility of such a circumstance, unless upon the supposition 
that such person foresaw the present discussion. The character, 
however, of Mr. Faraday for precision, renders it unnecessary to 
say any more, than that he informs me there is not the slightest 
ground for such a suspicion. 

I was no sooner convinced that the most carefully constructed 
barometers were liable to a slow and gradual deterioration in the 
manner which I have indicated, than I endeavoured to find a 
remedy to the evil ; without which, it is clear, that some of the 
most interesting problems of meteorology must be for ever left 
in a state of vagueness and uncertainty. For a long time I de- 
spaired of success ; but when at length I discovered an effectual 
method of preserving the Torricellian vacuum, I flattered myself 
that the Royal Society would so far have taken an interest in the 
subject as to have ordered it to be submitted to a trial, which 
could not have been so satisfactorily made under any other super- 
intendence. 

I soon perceived that the only possibility of effecting the ob- 
ject which I had in view, consisted in discovering some method 
of making the mercury wet (if I may be allowed the term) 
the tube in which it is contained. I was fearful, at first, that all 
the substances to which its attraction is sufficiently strong for 
this purpose, would be so much acted upon as to become disinte- 
grated or dissolved. I, however, fortunately recollected that, in 
some experiments in which I was formerly engaged, platinum, 
immersed in boiling mercury, became completely coated by it, 
and afterwards retained its coating for a long time. I repeated 
the experiment with some platinum foil, and found it to succeed 
perfectly. The mercury adhered strongly to the foil, and the 
latter, after a long immersion, was found to have lost none of its 


88 Mr. Daniell on the Barometer. 

tenacity. I availed myself of this property in the following 
way : — I caused a small thin piece of platinum tube to be made 
about the third of -an inch in length, and of the diameter of the 
glass tube ; this was carefully welded to its open end, so that the 
barometer tube terminated in a ring of platinum. The tube was 
filled and boiled as usual, and the infiltration of air was com- 
pletely prevented by the adhesion of the mercury, both to the 
interior and exterior surface of the platinum guard. I have no 
doubt that a mere ring of wire welded, or even cemented upon 
the exterior surface of the glass, which would be a much easier 
and less expensive operation, would be a sufficient protec- 
tion, as the slightest line of perfect contact must effectually ar- 
rest the passage of the air : but in the first attempt I was de- 
sirous that the experiment should be tried in the most perfect 
manner. When a piece of glass, armed either with a ring or 
tube, is immersed in mercury, the effect is easily perceived ; in- 
stead of any depression being visible around it, the mercury may 
be lifted by it considerably above its proper level. Time, of 
course, will be requisite fully to confirm the efficacy of the 
guard, and I was in hopes that the Royal Society would have 
attributed weight enough to the observations which I submitted 
to them, to induce them to give orders for the construction of a 
large barometer, upon the principle which I have suggested, to 
be placed beside the two others already in their possession. An 
opportunity would thus have been afforded of determining, in the 
most unexceptionable manner, several facts of the utmost im- 
portance to meteorological science. The further experiments 
which the council have called for, before they would commit 
themselves by the publication of the foregoing opinions, are in 
progress, and shall be laid before the Society as soon as they 
are complete ; but they obviously require considerable time for 
their progress. I have taken the pains to re-write this paper, 
under the conviction that advantage will be derived to science, 
by sooner throwing the subject open to general observation and 
experiment. 

I expected to have been able to find some evidence of the de- 
terioration of barometers in the numerous registers that are kept 


Mr. Daniell on the Barometer. 89 

of their oscillations : but I have not discovered any which have 
been continued for a sufficient length of time, with the same in- 
struments, to answer this purpose satisfactorily. Instances abound 
of observers having taken the pains to re-boil their barometers 
from air having obtained admission, in some unknown way 
which has always been attributed to accident ; but the fact of 
their gradual deterioration cannot, in this way, be established so 
completely as might have been supposed. 

The register of the Royal Observatory at Paris has only been 
published since the year 181G, in the Annates de Chimie ; a pe- 
riod which is not sufficient so far to neutralize the annual oscil- 
lation as to afford the means of a satisfactory comparison. 
Mr. Howard, however, in his work upon the climate of London, 
states the mean height of the Royal Society's barometer for ten 
years, from 1797 to 1S06, to be 29.882 inches, while for the ten 
succeeding years it is only 29.849 inches, which gives a depres- 
sion of .033 inches in that interval. 

The observations of the following ten years will not, I fear, 
be available in the same comparison, from the carelessness with 
which they have been made. 

The difference in the height of the old and new barometer, 
which have now been placed side by side, was, in the latter part 
of the year 1824, .07 inch, upon a mean of twenty observa- 
tions ; the new barometer standing upon the average so much 
higher than the old one. Whether this be wholly owing to de- 
terioration, it is not possible to say ; for the old barometer does 
not appear to have been boiled : but from the well known accu- 
racy of Mr. Cavendish, under whose superintendence it was con- 
structed, it is impossible not to ascribe a great portion of it to 
this cause. The mercury of this instrument is now thickly 
studded with air-bubbles of much larger size than those of the 
new barometer ; and when I last examined it, some of them 
were just upon the point of making their escape. 

I now feel that I ought not to allow this opportunity to pass 
without making a few observations upon the new meteorological 
register lately published in the Philosophical Transactions. I am 
aware that, in so doing, I shall run the risk of being again de- 


90 Mr. Daniell on the Barometer. 

signated as hostile to the council of the Royal Society ; but I am 
encouraged when I consider that it is only by inferior minds that 
the correction of errors, and the suggestion of improvements, in 
the pursuits of science, can ever be considered as acts of hostility. 

Great expectations, it is well known, were raised when it was 
announced that a committee had been appointed, consisting of the 
leading men of science, to take into consideration the state of 
the meteorological instruments and register of the Royal Society. 
I do not hesitate to affirm that the failure of an attempt, about 
this time, to establish a society to promote the science of meteoro- 
logy exclusively, was wholly owing to these expectations. Many 
persons, who would otherwise have concurred most heartily in the 
plan, waited to see the result of labours which they doubted not 
would effect the object in view ; and feared that the new society 
might bear too much the features of opposition: — as if any thing, 
which had in view the promotion of science, could be considered 
as opposed to the Royal Society ! The unusually-protracted time 
of the publication of the register contributed to keep alive these 
expectations. At length, in the beginning of the year 1825, ap- 
peared the long- looked -for journal of 1823, — but no report from 
the committee ! not one word of preface ! not a syllable about 
the instruments ! A most disheartening similarity in the appear- 
ance of the arrangement is the first thing to strike the eye ; and 
it is only by a close examination that it can be inferred that 
changes, and those very important changes, have been made. 

The register is divided as before into ten columns, and the im- 
provements commence with the first, which contains the dates of 
the month. To these are now prefixed the signs of the planets, 
to denote the days of the week ! The alteration, at all events, is 
harmless ; which, I fear, is more than can be predicated of all the 
others. From the second column we may collect that the times 
of observation have been changed to 9 A.M. and 3 P.M., except 
not a few instances, in which it is to be presumed that these hours 
did not suit the observer's convenience. Why the change was 
made is left to conjecture. The title of the third column an- 
nounces, for the first time, that the barometer is " corrected." 
But how corrected ? Is it the instrument itself which is corrected 


Mr. Daniell on the Barometer. 91 

for any faults in its original construction? or its indications, 
which are corrected for adventitious circumstances ? Is it cor- 
rected for capillarity ? for temperature ? or for any variation in 
the level of the mercury in its cistern ?J If it be a new barometer, 
is it of the siphon or cistern construction. If of the latter," what 
are the relative capacities of its tube and cistern 1 what the dia- 
meter of its tube ? Is there any and what difference between its 
indications, and those of the old instrument ? A comparison of 
the utmost moment. The only criterion by which we may con- 
jecture that a new instrument has been substituted for the old 
one is, that the height is now registered to thousandths instead 
of hundredths of an inch. But will it be believed that the coun- 
cil of the Royal Society would suffer such gross negligence to 
appear not only under the sanction of their " order," but after 
all the pomp and circumstance of a committee specially appointed 
to superintend the necessary arrangements ? The fourth and 
fifth columns contain the indications of the thermometers. The 
latter is headed M Thermometer Without." Whence, I presume, 
it is fair to infer that the other is, as before, " Thermometer 
Within." And yet this is entitled, in some places, M Six's Ther- 
mometer," and in others, H Register Thermometer." And we 
are told in the first note, " Six's thermometer deranged, and a 
horizontal register thermometer substituted for it." But then 
what does it register ? There is but one observation in the day 
recorded ; it cannot be the maximum, because in many cases the 
" thermometer without" is higher. It cannot surely be the 
minimum, for who would take that from an interior thermometer 1 
However, before three months have elapsed, note the second 
informs us H Register thermometer deranged." Then comes 
an hiatus valde dejlendus of a month, and we return once more to 
Six's thermometer and two observations per day — but how re- 
paired, and where placed, we are not informed. 

Thai- sixth column is entitled " Daniell's Hygrometer," and 
contains, I presume, though nobody but myself is bound to con- 
jecture this, the dew-point. 

The seventh column records the M degrees of moisture," but 
whether calculated from the same instrument, or from any other 


92 Mr. Daniell on the Barometer. 

hygrometer, is not stated. If from the former, the situation of 
the thermometer by which the calculation is made should have 
been most particularly determined. 

The eighth column contains the register of the rain ; and from 
the greater frequency with which the amount has been lately 
entered, we mayconclude that the soot from the old chimney-cowl, 
under which the gauge is situated, is more frequently removed 
from the pipe than it used to be. 

The ninth and tenth columns, recording the direction and force 
of the wind, bear every mark of their former accuracy ; and the 
only remarkable fact is the very rare occurrence of any variation 
of the strength from the standard 1. 

The eleventh and last column rings most edifying changes 
upon " rain," f« cloudy," " fine." 

The results of all this labour are summed up at the end of the 
journal in one short table, containing the means and extremes of 
the months, and the mean results of the year. From what data, 
or from what part of the register, the means of temperature are 
collected, it is very difficult to conjecture. From the note at the 
foot of the last page we learn that the barometer is now 100 
feet, instead of 81, above the level of low water spring-tides at 
Somerset-House; and that the rain-gauge is still 114 feet above 
the same level ; but by some chance or other, six inches nearer 
the ground than before. 

The importance which attaches to such minutiae as these, when 
undertaken by such a body as the Royal Society, cannot be better 
illustrated than by a circumstance which has lately been disco- 
vered, in determining the length of the second's pendulum ; a 
measure upon which depend all the late parliamentary proceed- 
ings for regulating the weights and measures of the united 
kingdom. 

The council, by whose orders the height of the barometer above 
the level of the tide was determined, little foresaw at the time that 
this simple operation could have any reference to proceedings of 
such importance : and yet hear what Captain Sabine says. 

" The height of the pendulums in Mr. Browne's house, in Lon- 
don, being here described as 92.5 feet above the level of the sea, 


Mr. Daniell on the Barometer, 93 

whilst in Capt. Rater's memoir in the Philosophical Transactions, it 
is stated to he 83 feet only ; it is necessary to explain that Capt. 
Rater's estimation of the height was founded, in part, on the un- 
derstanding (on the autliority of the Royal Society) that the elevation 
of their barometer at Somerset-House is 81 feet above low-water 
mark ; hut as the latter elevation has been since corrected by Mr. 
Bevan, who has determined it, by levelling, to be 90.5 feet above 
the mean level, the height of the pendulums must now be con- 
sidered as 92.5 feet, and is so esteemed by Captain Rater*." 

The same national work is also much affected by the want of 
such standard instruments as it is the appropriate province of the 
Royal Society to provide and preserve. Is it to be tolerated that 
results of such national importance should be made to depend for 
their verification upon a comparison with a thermometer, the pro- 
perty of a private individual ? The uncertainty in the experi- 
ments arising from such a cause may, according to Captain 
Sabine, amount to " not less than T %th of a vibration per diem ; 
being greater, as he had reason to believe, than the sum of the 
uncertainties due to all other causes whatever t." 

Surely these considerations, urged from so many quarters, must 
at length excite the dormant energies of those to whom the honour 
of the Royal Society i3 committed. If it be more consistent with 
the dignity of that venerable body to give up the working depart- 
ments of science, and to sit as judges only of the exertions of 
others, let them announce such intention openly, and there will 
then be many come forward in the field from which they retire. 
In most branches of science this is the course which has been 
already adopted ; and yet they have, perhaps, enough to do as im- 
partial dispensers of those honours for which there are so many 
competitors. But if they are still determined to persevere in causing 
observations to be made " by their order," in the only branch of 
natural science which now remains to them, let them at least pro- 
vide that they be made with all the care and precision which the 
actual state of that science demands ; for upon this the honour 
of the Society is at stake. 

* Experiments for determining the figure of the Earth. By Edward Sabine, 
&c. p. 343. t Idem. p. 182. 


94 


Art. XIV. ASTRONOMICAL AND NAUTICALi 
COLLECTIONS.— No. XXIII. 

i, A Method of Computing the Sun's Horizontal Pa r a llax from 
Observations of the Transits of Venus. By Thomas Hender- 
son, Esq. 

The method of computing an occultation of a fixed star by the 
moon, explained in No. XX. of these Collections, Art. III., may be 
applied with advantage to solar eclipses, occultations of the pla- 
nets, and transits of Vertus and Mercury. In each of these pheno- 
mena, the sun or planet occulted is to be substituted for the star, 
in the precepts given for occultations, and in transits, the planet is 
to be substituted for the moon. The orbital angle, in place of 
being constant as in occultations of stars, will (owing to the mo- 
tion of the sun or planet) undergo a small variation equal to the 
change in the sun or planet's angle of position, which, when great 
precision is requisite, must be allowed for ; and in transits, the 
complement of the orbital angle, and the side of the right-angled 
triangle, mentioned in Precept III., will have the contrary signs to 
those prescribed for occultations, by reason of the planet's retrograde 
motion. The difference of the horizontal parallaxes of the two 
bodies is to be employed in place of the horizontal parallax of the 
moon ; and, while the semidiameter of the moon, or occulting 
body, remains without augmentation, the semidiameter of the sun 
or planet undergoing occultation, is to be diminished by a small 
quantity, obtained from this formula, 
s sin p sin A, 
where s denotes the semidiameter to be diminished, p the hori- 
zontal parallax of the other body, and A the altitude of the sun 
or planet. The sum or difference of the semidiameters will be 
employed according to the particular phenomenon to be investi- 
gated. 

These modifications of the rules for occultations being observed, 


Astronomical and Nautical Collections. 95 

the sun's horizontal parallax may be thus determined from obser- 
vations of the transits of Venus. 

If the sun's horizontal parallax be supposed known, the hori- 
zontal parallax of Venus is ascertained from the ratios of the dis- 
tances of Venus and the sun from the earth. By means of these 
parallaxes, the observed times of ingress and egress at those places 
where the beginning and end of the transit have been observed, 
and other astronomical data, the nearest distance of Venus from 
the sun, as seen from the earth's centre, is to be computed in the 
same manner as the moon's latitude is determined from observa- 
tions of an occultation. See La Lande's Astronomy, third edition, 
Arts. 1970-1976. In this calculation the orbital and perpendicular 
parallaxes are to be adopted, instead of the parallaxes in longitude 
and latitude employed by La Lande, and the motions are to be 
referred to Venus's relative orbit in place of the ecliptic. If the as- 
sumed parallax, the observations, and other data, be correct, the 
nearest distances, deduced from the observations at the respective 
places, ought to be equal. But if they turn out to be different, 
that value of the sun's parallax should be preferred which gives 
for the nearest distance quantities agreeing best with each other. 
This is to be determined by repeating the calculation upon a second 
hypothesis of the sun's parallax, observing that all the parallaxes 
will undergo a proportional variation. 

For an illustration of this method, the transit of 1769 is assumed. 
The times of observation at the different places, and the other 
data, are taken from De Lambre's Astronomy. 

At Otaheite, the total ingress was observed at 21 h 43 m 55*, and 
the beginning of egress at 3 h 14 m 3 s , apparent time. The sun's 
horizontal parallax at his mean distance from the earth being 
assumed 8"*7, Venus's nearest distance is found to be 606"*122 ; 
but the sun's parallax being assumed 8"-5, the same distance is 
found to be 606"*728. Hence an increase of one second upon the 
sun's mean horizontal parallax produces a diminution of 3"-030 
upon the nearest distance, deduced from these observations. If D 
denote the nearest distance, P the number of seconds by which the 


96 Astronomical and Nautical Collections. 

sun's mean horizontal parallax exceeds 8"-7, we have the following 
equation, 

D = 606"- 122 - 3-030 P. 
Making similar calculations for all the places, where the begin- 
ning and end of the transit were observed, the following equations 
are obtained : — 

Otaheite . . . . D = 606"-122 - 3-030 P 
California . . . D = 606 '430 — 1*180 P 
Hudson's Bay . D = 606 -560 + 0-915 P 
Wardhus . . . . D = 605 -150 + 2-985 P 

Kola D = 606 -109 + 3-035 P 

Resolving these equations by the method of minimum squares, 
to obtain the most probable values of D and P, D will be found to 
be 606M28, and P + 0"-0988, making the sun's mean horizontal 
parallax 8"-7988, or 8"-8. 

The other results, usually deduced from transits, such as the 
times of nearest approach and ecliptical conjunction, the difference 
of longitude of the various places, Venus's latitude at the conjunc- 
tion, the distance from the node, and the duration of the transit, 
'ndependent of parallax, may now be determined in a manner which 
it is unnecessary here to explain. 

On comparing this method with those of La Lande, Maskelyne, 
De Lambre, and Biot, it appears that in the former the final result 
is not (as in the latter) deduced from quantities, such as Venus's 
nearest distance, chord described during the transit, latitude, and 
elongation, which cannot be known with accuracy, until the paral- 
lax be determined. 

ii Remarks on the Discordances observed between the Lunar Ob- 
servations at Greenwich and Paris. By Thomas Hen- 
derson, Esq. 

Annexed is a state of the discordances between the solar and 
lunar observations at Greenwich and Paris, in the years 1800-9, 
mentioned in Astronomical and Nautical Collections, No. XXI. 
Art. II. 


'■ lll.MUIUi .III ..M] . ..Is 

-an oqj Xq jajiuiwip 

f.UOOjy JO >■ |ii.iu...i u, 

-uiii ... .. .u.ii.. H i,| 


jo MOKmilp u«.»HJ 


SC 1" t» X X 90 
i": /. o /. t ?: 


XX 


.. ir.U in <|iiii | |.u . i >- 

h.uooivjo'H'V 
jo ajudi>nip imajv 


•.. >r.U til qui|( 
jwy '.uoojv jo -u'v 

jo .' m..j.i U i |. u«ajv 


' VI.'1'.-VJ < ■{! ) 
II >L'.l )H (KUIMttUO.) 
Ml' IS .1" J.«1UIII>4 


•axioo jo jiquiii^ 


wii ^ i^o n 


mm 


HXt.OliflO 
1111++ 


firsaMa 


WW 


§s 


X?t £ 


■ —2 

f-l cj bO 

2 oo 


i /J 30 CO X 


o o t> o « o .3 

Cv 0) CU CU 4) 0) 


o © 


l-H F-l «i 


o o o o 

CO 00 CO "JO 


bfi • 


aa 

£2 

.-- 


BOP* *■!»■»»»« 

aaaaaa 

222222 

_ _ _ — — _ 


OCA 
CO O 


W 


+ i 


-j 


M 34 

O CO 


Is 

II 


s 
I 

■ 

ii 

<n — 

— <« 

a •> 

•0 V 

■: = 


lit 

lil 

fJa 

HI 


11 8s 

ill 

w « *» 

■c ja -a 

K 2 


jo aouaoajjip ueajv 


7* 


OtfrtOOH 


•AaoiHMssiio tpea 

18 paieduioa 
Mirjsjo JW<liutiM 


£3 
ii ex 


oaoxo a. 


suopc.ijaeqo Buipuods 
-ajuoj jo joquin.v 


«/3 © 


8 «j 


■fc SS 


la 


^S 


a* « 

o 

33 C 


O U CO 

*J= CO 
fa ££ 


i hi * 

g» <* a 

o 


S2 


Vol. XX. 


II J 

2 2 -< 

-- 


M 


S X X CO c? 


« w o o > « 

«w eu <u qj o 5 


030000 

SSf Sx'*' 

PH P* P* p* p* »H 

S-g J S 9 9 


a a a a a a 
222222 

pn fa pm fa fa fa 


QQ 

P* pH 
CMS* 

33 


<fa 


ii 

£2 

- - 


la 7 

= / o 

1 S s 

u J, = 


K i 

s* E 

SI s 

rf 

5 1 

I "2 


98 Astronomical and Nautical Collections* 

In these calculations the difference of meridians is assumed 
9' 20"'5, which has been deduced from the corresponding occulta- 
tions of fixed stars by the moon, observed at both places, during 
the period in question. 

On comparing the catalogues of fixed stars by different astrono- 
mers, similar discordances are found to subsist between the places 
of several stars relatively to those of the others by the respective 
catalogues. For instance, the relative position of Castor, in right 
ascension, differs 0"-31 of time, or 4"*6 of space, in Mr. Pond's 
and M. BesseFs catalogues. Nautical Almanac for 1822, p. 179. 
It would thus appear that the discordances alluded to are not pe- 
culiar to observations of the sun and moon, but that they are com- 
mon to all the celestial bodies, and are occasioned by the unavoid- 
able imperfections in the present state of the art of observing. It 
may be remarked that, while these imperfections continue, the dif- 
ference of longitude determined from observations of the moon's 
meridian right ascension cannot be so accurate as that deduced 
from corresponding observations of occultations. Thus, while the 
difference of longitude between Greenwich and Paris, by eight 
occultations is 9' 20"*5, the above series of 395 observations of 
right ascension makes the same difference of longitude 9' 24"*8. 

iii. The Latitude of Greenwich, as computed by Professor 
Bessel. 

In the 73rd Number of Schumacher's Nachrichten, we find a 
paper of Professor Bessel on the results of the Greenwich observa- 
tions for 1822, comprehending a number of altitudes obtained by 
reflection as well as by direct vision. The latitude, from the mean 
of a great multitude of observations of different stars, becomes 
51° 28' 38"-343 + b', b' t being a quantity so small that it may 
be neglected, though it has not been precisely determined. The 
mean error of each single observation is ;£ 0""799, and is no 
greater for the observations made by reflection than for the others ; 
a circumstance which proves the extreme care that must have been 
taken to avoid the effects of agitation. 


Astronomical and Nautical Collections. 


99 


The declinations of the principal stars deduced from this volume, 
employing Bessel's refractions, agree rather better with the 
Konigsberg catalogue, than with Mr. Pond's own standard cata- 
logue. 

On the other hand, it is remarkable that the determination of the 
latitude of Greenwich agrees much better with Mr. Pond's former 
computation, than with that which Professor Bessel had deduced 
from Bradley's observation. The former was 51° 28"37"-95, the 
latter 51° 28' 39"-60 ; the differences being — 0"-393 and + l<'-257. 

In speaking of the longitudes of places from Greenwich, as ex- 
pressed in time, it was cursorily observed in the last number of 
these collections, that the time intended is, strictly speaking, side- 
real. This expression was employed as leading to a result which 
is unexceptionable, although Mr. J. I. has very properly remarked 
that it is liable to misconstruction, and that in questions relating 
to solar time the difference in longitude may, without error, be 
considered as reckoned in solar time, and not in sidereal. 


iv. Bessel's latest Fundamental Catalogue of Stars, deduced from 
his Observations in the last five years. Schum. Nachr. No. 78. 


Yearly change 
R, A. 1825. 1825. 

y Pegasi 4 14-059 3*0790 

« Arietis 1 57 19*619 3*3566 

* Ceti 2 53 8413 31232 

« Tauri 4 25 53-265 3*4298 

a Auriga 5 3 46*523 4*4139 

Ononis 5 6 7*831 2*8785 

Tauri 5 15 14*128 3*7857 

a Ononis 5 45 41*963 3*2453 

a Canis major. . . 6 37 26-048 2-6441 

a Geminor. med. . 7 23 24*848 3*8430 

a Canis minor ... 7 30 8*172 3*1471 

Geminorum ... 7 34 35*645 3*6851 

u Hydrae 9 18 59*154 2-9474 

« Leonis 9 59 2-552 3*2050 

H 2 


Secular 
alteration. 


+ 0*0097 
+ 0*0201 
+ 0*0097 
+ 0*0109 
+ 0-0184 
+ 0*0043 
+ 0*0089 
+ 0-003 1 
+ 0-0004 

- 0*0125 

- 0*0044 

- 0*0122 

- 0-0015 

- 0*0102 


100 Astronomical and Nautical Collections. 

YeATly chang* fieouiar 

R'.A. 1835. 1S25. alteration. 

U M s S 

Leonis 11 40 7-577 3-0667 - 0-0077 

Virginis 11 41 34-743 3-1244 —0-0006 

a Virginis 13 15 59-118 3-1459 + 0-0112 

« Bootis ....... 14 7 40-911 2-7323 + 0-0012 

1 « Libra ..... 14 41 1-368 3-3000 + 0-0156 

2 a Libra? .... 14 41 12-738 3-3020 + 0-0155 

a Coronse 15 27 16*823 2-5364 + 0024 

« Serpentis .... 15 35 39-245 2-9491 4- 0-0063 

a Scorpii 16 18 41-517 3-6616 +0-0157 

a Herculis 17 6 40-286 2-7306 + 0-0037 

* Ophiuchi .... 17 26 48-818 2-7771 + 0-0035 

a Lyrae 18 31 0-831 2-0300 + 0-0016 

7 Aquilae 19 37 56-371 2-8549 - 0-0008 

a Aquilae 19 42 14-637 2-9286 - 0-0014 

Aquilae 19 46 43-025 2-9501 - 0-0015 

1 « Capricorni . . 20 7 56-495 3*3331 —0-0081 

2 a Capricorni . . 20 8 20*327 3'3375 — 0-0081 

u Cygni 20 35 28-088 2-0413 + 0-0024 

a Aquarii 2J 56 47*581 3-0838 - 0*0043 

a Piscis Austr. . . 22 47 57*812 3-3402 - 0-0217 

a Pegasi 22 56 2-973 2-9812 + 0-0053 

a Andromedse . . 23 59 21-515 30777 + 0*0177 

Notwithstanding this extreme accuracy in taking the mean of 
observations to a single ten-thousandth of a second in time, it is 
rumoured that between Professor Bessel and another experienced 
astronomer, there is a " constant difference in observing the right 
ascension," amounting to " nearly a whole second of time," as 
•was " ascertained for some months during his stay" at that astro- 
nomer's house : and the preceding remarks of Mr. Henderson 
sufficiently confirm the credibility of such a rumour. 

v. Abstract of Captain Sabine's Experiments to determine the figure 
of the Earth. Printed at the expense of the Board of Longitude , 
4/o, London, 1 825. 

* " In the year 1816, an address to the Crown was moved in the 


Astronomical and Nautical Collections* 101 

House of Commons by Mr. Davies Gilbert, praying that his Ma- 
jesty would be graciously pleased to give directions for ascertain- 
ing the length of the pendulum vibrating seconds of time in the 
latitude of London, as compared with the standard measure in the 
possession of the House of Commons ; and for determining the 
variations in length of the said 'pendulum at the principal stations of 
the trigonometrical survey extended throughout Great Britain. His 
Majesty's Ministers having requested the assistance of the Royal 
Society in carrying into effect the objects of the address, their ac- 
complishment was undertaken by one of the most distinguished 
members of that society, and completed in 1819; and the account 
was published by Captain Kater, in the Philosophical Transactions 
for that year." P. xi. xii. 

" The discrepancies, however, of the results obtained, by 
combining the lengths of the pendulums observed at the dif- 
ferent stations in Great Britain and in France, were so great and 
so irregular, as to prevent any independent conclusion whatsoever, 
relative to the general figure of the earth, being drawn from the 
experiments, either of the French philosophers or Captain Kater." 
P. xiii. 

" Such was the state of the inquiry when the present experi- 
ments were undertaken ; their design was, to give the method of 
experiment the advantage of being tried under the circumstances 
most favourable for the production of a conclusive result ; to ex- 
tend the suite of stations previously confined to Great Britain and 
France, to the equator on the one side, and to the highest 
accessible latitudes of the northern hemisphere on the other; to 
multiply the stations at both extremities of the meridian, so that by 
their general combinations the irregular influences of local density 
might mutually destroy each other, and the variations of gravity 
due to the ellipticity alone be eliminated ; and to ensure the uni- 
formity of procedure and strict comparability of the results at all 
the stations, by the unity of the observer, and the identity of the 
instruments." 

The experiments were made with a detached pendulum supported 
by a knife edge, of which the oscillations were compared with those 


Astronomical and Nautical Collections. 

of the pendulum and an astronomical clock nearly in the manner 
employed by Captain Kater, but with some little improvement in 
the mode of determining the instants of perfect coincidence. They 
were repeated in most cases with two different pendulums of the 
same form, and the greatest care was taken to preserve the identity 
of the circumstances in all the experiments ; it was even found that 
the changing the pieces of agate, which supported the knife-edges, 
affected one of the two pendulums a little differently from the 
other ; and allowance was made for this diversity when required. 
Perhaps, however, all such irregularities might have been more 
easily avoided by using a blunt point on each side rather than a 
knife-edge ; the knife-edge was required in Captain Kater's expe- 
riments on the length of the pendulum, for the purpose of obtaining 
a precise line from which the length could be measured ; but there 
was no such necessity where the comparative frequency only of 
the vibrations was concerned. 

With the most laudable zeal to omit no confirmation that could 
be obtained for the accuracy of his results, Captain Sabine repeated 
his experiments at all the stations, in a manner totally different, 
with pendulums forming parts of actual clocks, but resting like 
the others on knife-edges, instead of being suspended by springs. 
The results agreed with those of the detached pendulum as nearly 
as could possibly be wished, the irregularity never amounting to 
more than two vibrations in a day for any one station ; and the 
mean inference, with respect to the figure of the earth, being al- 
most exactly the same for both series. 

The grand ultimate result of all the operations at the thirteen 
stations, deduced by the modern method of computing the proba- 
bility of least error, as well as from the most natural mode of 
grouping the observations, affords us an ellipticity equal to j-^ 
of the earth's-axis. 

Taking it for "granted that this is the true measure of the earth's 
compression, we may proceed to inquire what are the inferences 
from the determination, respecting the central and superficial den- 
sity of the earth. It will then appear from Dr. Young's calcula- 
tion of the effects of compression, inserted in this Journal, Vol. IX. 


Astronomical and Nautical Collections. 103 

p. 33, that supposing the mean density to be, according to the expe- 
riments of Maskelyne and Cavendish, about 5.4; the mean super- 
ficial density must be 3 • 08, which is rather greater than could have 
been previously conjectured; the modulus of elasticity 10,800,000 
feet, a little exceeding that of glass or of iron. This excess, however 
is not sufficient to afford any very decided argument in favour of the 
existence of a central fire, since it is very probable that the mo- 
dulus increases when the compression becomes extreme, even 
without any elevation of temperature. The central density, from 
the same little table, is found 13*95, or somewhat greater than 
that of quicksilver. 

The length of the pendulum vibrating seconds at the various 
stations of Captain Sabine's experiments is found in page 333, re- 
duced to the level of the sea, upon a probable supposition of the 
general density of the superficial parts of the earth, as suggested 
by Dr. Young, which would only require a very slight modification 
from the present determination of j-Jg , as the comparative super- 
ficial density. 

Latitude. Length in a vacuum 

Stations. reduced to the 

O / // level of the sea. 

St. Thomas 24 41 N. 39-02074 

Maranham 2 31 43 S. 39*01214 

Ascension 7 55 48 S. 39*02410 

Sierra Leone ..... 8 29 28 N. 39*01997 

Trinidad . 10 38 56 N. 39*01884 

Bahia 12 59 21 S. 39*02425 

Jamaica 17 56 7 N. 3903510 

New York 40 42 43 N. 39*10168 

London 51 31 8 N. 39*13929 

Drontheim 63 25 54 N. 39*17456 

Hammerfest 70 40 5 N. 39*19519 

Greenland 74 32 19 N. 39*20335 

Spitzbergen 79 49 58 N. 39*21469 

The results of different combinations of these experiments with 
others, page 352, are expressed in this table : 


104 Astronomical and Nautical Collections, 

Ellipticity. 

From Captain Sabine's 13 stations 1 : 288-4 

From these 13 and 8 stations of the French . . 1 : 288*7 

From these 13 and 7 British stations 1 : 289*5 

From the mean of 5 stations near the equa- > , , oos«3 
tor and 6 in Britain \ 

From the mean of 5 equatorial and the most ) , . 2 qq 4 
northerly 5 $ 

From the 6 British and the 5 northerly .... 1 : 288-5 

From the general combination of 25 stations 1 : 289*1 

Mean T7288-7 

" The attempt," says Captain Sabine, p. 352, " to determine 
the figure of the earth by the variations of gravity at its surface, 
has thus been carried into full execution on an arc of the meridian 
of the greatest accessible extent ; and the results which it has pro- 
duced are seen to be consistent with each other, in combinations 
too varied to admit a probability of the correspondence being acci- 
dental. The ellipticity to which they conform differs more consi- 
derably than could have been expected, from 30 1. 15 , which had 
been previously received on the authority of the most eminent 
geometrician of the age, as the concurrent indication of the mea- 
surements of terrestrial degrees, of pendulum experiments, and of 
the lunar irregularities dependent on the oblateness of the earth, 
In further attestation of the irreconcilability of the variation of gra- 
vity now manifested, with the ellipticity inferred in the memoir in 
which the Marquis de Laplace has discussed the results of previous 
observation and experiment, it may be noticed that if each of the 
tropical stations which I have visited be severally combined with 
each of the stations within 45° of the pole, no one result, amidst all 
the irregularities of local attraction, will be found to indicate so 
small a compression as that of previous reception." 

Taking 39*1391 for the mean length of the pendulum in London, 
latitude 51° 31' 8"*4, Captain Sabine observes, that it might pro- 
bably vary almost the two-hundredth of an inch above or below 
this length in different points of the same parallel of latitude, and on 


Astronomical and Nautical Collections, 105 

the same level of the sea ; and that at the equator its mean length 
must be about 3901 inches. 

" The comparison of different methods of ascertaining the 
length of the pendulum is highly important," says Captain Sabine, 
page 37 1 ; " and by consequence the invention of new modes of 
procedure. It is understood that a third method has been proposed 
by Dr. Young, by means of a weight sliding on a rod, or bar, with 
a single axis of suspension, as a yet more convenient method of ob- 
taining a correct standard, than the processes of Borda and Kater. 
It would be highly interesting to ascertain, by competent trial, the 
relative values of the three methods, and to examine the corre- 
spondence of their results ; or rather to work at them until they 
should correspond, or until the reason of a difference should be 
apparent." 

Without denying the justice of this conclusion, it may be re- 
marked, that it is hardly fair either to Captain Kater, or to its in- 
ventor, to call Dr. Young's lt a third method ;" because it was 
suggested to the Committee of the Royal Society, and approved 
by them, before the date of Captain Kater's very ingenious contri- 
vance, and therefore before the demonstration of Laplace, which 
showed that perfect sharpness was not necessary to perfect accu- 
racy in the result of the convertible pendulum, and before that of 
Dr. Young, which proved that the effect of a temporary compression 
of the sharp edge would be inconsiderable, neither of which indis- 
pensable circumstances were foreseen by any person at the time 
that Dr. Young thought his more complicated arrangement neces- 
sary ; any more than it could be foreseen with what admirable deli- 
cacy of experiment, or with what persevering iudustry, Captain 
Kater would overcome the difficulty of making his measurement 
from one of two opposite sharp edges to another, instead of the 
much more convenient process of reading off by a micrometer the 
distances of the fine lines only, which were to be drawn on the rod 
of Dr. Young's pendulum. 

It is indeed doubtful whether any future experimentor would be 
likely to obtain a result so nearly agreeing with Captain Kater's, by 
his own method, as by that of the sliding weight, in which so little 


106 Astronomical and Nautical Collections. 

is left to the discretion or management of the observer. The appa- 
ratus has long been open to the public inspection in the Royal 
Observatory at Greenwich. The reason that no results have been 
obtained from it, is the failure of the clock-work by which it was to 
be kept in motion, and which was intended to act by a single re- 
coiling stroke at the lowest point of the vibration, but which was 
not so executed as to comply with that necessary condition. But 
this difficulty might readily be overcome by any person who would 
undertake to make the experiments by means of coincidences, it 
being only necessary for this purpose to be provided with a clock 
with four different pendulums of different lengths, capable of having 
their coincidences observed in the different places of the weight to 
be employed. The mode of computation is shown in the Philoso- 
phical Transactions for 1818. 

Captain Sabine doubts altogether of the perceptible effect of a 
ship's magnetism on the rate of any good chronometer, and those 
of Messrs. Parkinson and Frodsham he found altogether exempt 
from it. Page 392. 

Captain Sabine has also given us the results of a multitude of 
experiments for determining the variation in the intensity of ter- 
restrial magnetism, page 460. He seems to have ascertained that 
the agreement between the intensity and the magnetic latitude, as 
computed according to the approximation derived from theory, is 
more regular than the connexion between the dip and the intensity ; 
but this is far from being an exception to the validity of the theory 
in the form first published in this Journal, as might be inferred from 
the manner in which Captain Sabine has stated it ; on the contrary, 
it is more easily conceivable that local causes of disturbance should 
affect the direction than the magnitude of the magnetic force in 
any spot, as is obvious from the laws of the composition of forces ; 
for the hypotenuse of a triangle, of which the legs are very un- 
equal, differs very little in length from its longer side, though its 
direction may be considerably different. 

The situation of the magnetic pole Captain Sabine finds it most 
convenient to place in latitude 60° N., longitude 80°, or rather 
78° W. He then finds the magnetic force, as computed by Dr. 


Astronomical and Nautical Colteclwv Wt 

Young's theorem, and as obtained from his own very accurate ex- 
perimental determination, both by the horizontal and the dipping 
needle. 

Exper. Cowtput 

At St. Thomas 1-045 1*005 

Ascension 102 1-01 

Bahia 1-02 T04 

Sierra Leone 1*19 1*15 

Maranham 1-16 1*18 

Gambia 1-28 1*24 

PortPraya 133 1*31 

Teneriffe 1-49 1*45 

Trinidad 1-39 147 

Madeira 1*55 1'52 

London 1*62 1-62 

Jamaica 1-62 1*63 

Cayman ; . . 1-63 1*65 

Drontheim 1*64 1*67 

Hammerfest 1*69 1*68 

Havannah 1*72 1-71 

Spitsbergen 1*78 1*78 

Greenland 1*75 1*85 

New York Td9 Til 

Shetland 1-70 1*70 

Davis Strait (a) .... 194 1*95 

Hare Island 1*94 1'95 

Davis Strait (6) .... 1*98 1-97 

Baffin's Sea (a) .... 1-90 194 

Baffin's Sea (b) 1-92 1-94 

Baffin's Sea (c) 1-98 1-94 

Baffin's Sea (d) I -99 1-94 

Davis Strait (c) 1*98 1-98 

Possession Bay 1.95 1*96 

Regent's Inlet T96 1*96 

Byam Martin's Island . . 1*93 1-93 

Melville Island 1*92 1-92 

Winter Harbour .... 1*90 1*92 

The greatest variation of the experiment from the computation 
is less than a seventeenth of the whole ; an agreement perfectly un- 
expected in an approximation exposed to so great irregularity. Dr. 


108 Astronomical and, Nautical Collections, 

Young, in 1807, had made the magnetic pole 15° more northerly, 
and 8° more easterly ; Biot 19° more northerly, and 50° more 
easterly ! 

In the experiments on the diurnal variation both at Hammerfest 
and at Spitzbergen, the needle seems to have passed its mean po- 
sition about half an hour before noon and midnight. 

The dip sector, employed for observing the depression of the 
horizon in the neighbourhood of the gulf stream, was found to afford 
very correct results, but less irregular than might have been ex- 
pected from the actual diversities of temperature of the sea and 
air concerned in the refraction ; the error of the tabular dip never 
amounting to two minutes. It was ascertained in Jamaica, by 
some delicate thermometrical experiments, that the heat commu- 
nicated by the sun's rays is very sensibly greater in the upper 
regions of the atmosphere, than on the level of the sea. A num- 
ber of important geographical and hydrographical notices, espe- 
cially relating to the currents in the Atlantic, are contained in this 
volume, together with appropriate charts. 

It is impossible to quit the subject of Captain Sabine's experi- 
mental labours without giving the strongest testimony of applause 
to his zeal and diligence and accuracy, and expressing a hope that 
he may find both private and public motives for continuing his 
exertions with equal ardour in the prosecution of further investi- 
gations connected with the advancement of physical science. 

vi. Extract from a Letter addressed by Professor Bessel to Pro- 
fessor Schumacher, relating to the Greenwich Observations. 

When I had the pleasure of being your guest at Altona, you 
showed me the numbers of the Philosophical Magazine, which 
contain a very severe censure of the Greenwich Observations for 
1821. I saw this censure with some surprise, because I had al- 
ways considered the collection of observations at Greenwich as 
singularly valuable, and as a rich source of astronomical truths » 
nor were you, I believe, of a different opinion; and we were per- 
fectly agreed respecting the unimportance of the inaccuracies that 
were imputed to this work in the two papers published in the 64th 
volume of the Philosophical Magazine. 


Astronomical and Nautical Collections. 109 

For those who are acquainted with the Greenwich observations, 
and who compare them with the critic's remarks, every further ex- 
planation would be superfluous ; but since it may be supposed 
that these remarks will fall into the hands of many persons not 
deeply versed in astronomy, I readily comply with the request 
Which you made, that I would commit to writing our common view 
of the subject. I feel, as well as yourself, the propriety of doing 
my best on the occasion, in order that too great importance may 
not be attached to this censure of an establishment, to which 
astronomy is indebted for a great proportion of its advancement; 
and that its importance cannot be very great, is sufficiently shown 
by the facility with which Mr. Olufsen has computed the declina- 
tions of the fundamental stars, as published in the Nachrichten, 
No. 73, from the Greenwich observations for 1822. 

The greater number of the errors which have been pointed out by 
the censor, are merely accidental errors of the pen. Errors of this 
kind are certainly disagreeable, and it would be better if they 
could be entirely avoided ; but since all collections of observations 
in existence do contain such errors, they clearly appear to be una- 
voidable. 

The first class of errors mentioned in the Philosophical Maga* 
tine contains the cases in which the mean deduced from the read- 
ings of the two microscopes A and B differs from the column in 
which that mean is assigned. Since there must be some manifest 
oversight in all these cases, it may sometimes be difficult to de- 
termine whether it is in the readings or in the mean assigned ; but 
it will, in general, be easy to distinguish, from the preceding or 
following observations of the same star, where the error lies. 

The second class contains the differences between different 
records of the same observation. These must be errors in the 
copies sent to the press, and not in the readings of the microscopes ; 
and they may generally be corrected by a comparison of the two 
passages : they sometimes extend to whole degrees, or to the tens 
of the minutes, and are then of no importance ; for example, in the 
observations of Procyon the 23d Feb. 1821, and of $ Cephei the 
8th Dec. where there are errors of 30° and 5° respectively. 


UO Astronomical and Nautical Collections. 

The sixth class of errors contains the intervals between the mi- 
crometer wires, as they are deduced from different observations of 
the same star. These are often dependent on errors of the pen, 
as in the observation of Capella on the 7th February, and in that 
of Sirius on the 8th, where there are errors of 5" and of 40" re- 
spectively in the fourth wire ; frequently also they arise from in«* 
accuracies of observation. In the former case they are of no con- 
sequence whatever, being easily detected at first sight; in the 
latter they are fundamental imperfections; but such imperfections 
are inseparable from the nature of observations, and it would be 
ridiculous to expect from an astronomer that he should perform 
impossibilities. All registers of observations exhibit inaccuracies 
of this kind, and if any should be produced without them, it might 
with confidence be asserted to be a forgery. The diligence of the 
astronomer is proved, not by the perfect agreement in his tenths of 
seconds, but by the magnitude of his mean or his probable error ; 
and it would probably be difficult for the critic to prove that this 
error is much greater in the Greenwich observations, than the 
nature of the instruments renders unavoidable. 

The errors of the fifth class, which comprehends the differences 
between the polar distances observed with two and with six micro- 
scopes, seem to me to have been introduced without the least 
propriety : they are either insignificant errors of the pen, as in the 
case of y Draconis, 28th March, or slight accidental errors of ob- 
servation, mixed with the changes of place of the stars and of the 
refraction, or, lastly, changes of the place of the pole on the instru- 
ment. For this last the observer can by no means be responsible. 
Had the critic pointed out any new method of fixing the instru- 
ment so that it should be subject to no alterations, he would have 
deserved the thanks of all practical astronomers ; but the constant 
result of past experience shows that the greatest possible care, in 
procuring a firm foundation for the pillars, affords us only a com- 
parative and not an absolute stability. The fixing of the instru- 
ments at Greenwich has been such as to keep them for a long time 
admirably firm; but at other times it has not been so successful, 
as may be seen in the table of the place of the pole, printed in the 


Astronomical and Nautical Collections. Ill 

Nachrichten, NO. 73 ; the differences between the latter days of 
July and the beginning of August, 1821, depending on a change 
of this kind, so that they cannot be considered as accidental errors 
of observation, nor are they of material importance, as they may 
be readily determined by a series of observations of the pole star, 
so complete as those which are made at Greenwich. The acci- 
dental irregularities of the polar distances, which remain after the 
correction of the place of the pole, can be as little considered as an 
imputation on the accuracy of the observer, as those of the inter- 
vals of the micrometer wires. The truth of this remark is illus- 
trated in the Nachrichten, No. 73. 

The fourth class contains the differences between the times of 
transits observed with the transit telescope, and the mural circle. 
The latter instrument, however, not being intended for the obser- 
vation of transits, nor being ever actually so employed, it would 
have been of no manner of use to seek for greater accuracy in the 
memorandums which are made merely with a view of determining 
its place with respect to the meridian. We ought to acknowledge 
the occasional insertion of these memorandums with gratitude, as 
they assure us that the instrument never deviates so much from 
the meridian as to aft'ect the polar distances ; but they are not in- 
tended for any other purpose. Neither Bradley nor Maskelyne 
have ever noted the times of the transits by their mural quadrant, 
although it was more liable to variation than the mural circle. But 
to correct the place of the axis of this circle continually, so as to 
bring it perfectly into the plane of the meridian, would certainly be 
of no advantage to the Greenwich observations. 

Other errors which are criticized, for example, those of the 
names of the stars, of the hour or minute of their transits, and so 
forth, are of no material importance whatever ; and how difficult 
it is to avoid errors of this kind, may be inferred from the circum- 
stance of my having found about 1400 such errors in Bradley's 
observations. [The catalogue of these errors is already printed at 
the expense of the Board of Longitude, and is to be annexed to 
the publication of Mayer's original observations, which is nearly 
completed.] 


1 J 2 Astronomical and Nautical Collections. 

The remark, that the observations at Greenwich are commonly 
concluded at midnight, -would be of some weight, if it could be 
proved that any thing essential is omitted by this practice, which 
does not appear to me to be the case. The observations relate 
chiefly to the sun, the fundamental stars, the moon, and the oppo- 
sitions of the planets ; and it may easily be discovered that these 
different series are exhibited with an uncommon degree of perfec- 
tion. Had the censor in the Philosophical Magazine pointed out 
any other series of observations which could have been combined 
with these, so as not to interfere with them, no doubt the Astro- 
nomer Royal would have been much obliged to him. Every thing 
cannot be done at once in an observatory ; and if as much is 
effected as can be wished in one respect, something must be 
omitted in others. But to multiply observations, without any plan 
or object whatever, would be mere idleness. Whoever is dissatisfied 
with the actual riches of the Greenwich observations, would do well 
to make the attempt to excel them ; he would convince himself by 
such an experiment that the labour and patience required for doing 
so much, are fully sufficient to exhaust the powers of any one man. 

The third class of errors, relating to the meteorological instruments, 
I have not yet mentioned, because I think myself that greater ac- 
curacy is required in this department than it has hitherto been 
usual to observe. And if I should be allowed to suggest any im- 
provement that could be made in the observations at Greenwich, 
it would be a more correct account of the meteorological instru- 
ments, and of the place in which the exterior thermometer is fixed. 
[It may, indeed, be expected with confidence that Professor Bes- 
sel's desire to possess a barometer and a thermometer, correctly 
compared with those which are employed at Greenwich, will not 
long be allowed to remain ungratified, though it would be a subject 
of much surprise on this side of the Channel, if he should detect in 
them such discordances as he is inclined to suspect.] 

[This letter has probably appeared in Professor Schumacher's 
Nachrichten, though the 84th number of that interesting collection^ 
for which it was intended, has not yet reached this country.] 


113 


Art. XIV. ANALYSIS OF SCIENTIFIC BOOKS. 

I. An Attempt to establish the First Principles of Chemistry by 
Experiment. By Thomas Thomson, M.D. Regius Professor of 
Chemistry in the University of Glasgow, F.R.S., Lond. and 
Edin., &c. &c. In Two Volumes. London, 1825. 

The well-known author of this work regards the soul and body 
of chemistry to consist in a knowledge of the relative weights of 
the combining substances. This is to form a very narrow concep- 
tion of the science. The true function of the chemical teacher is 
announced in the following verse of the Roman poet : 

In nova fert animus mutatas dicere formas 
Corpora. 

It is the characteristic of chemical genius to reveal new ele- 
mentary bodies, to form new compounds of the elements known 
before, to discover new qualities and relations both among simple 
and complex substances, and to arrange the manifold and marvel- 
lous phenomena of corpuscular action, under a few general laws. 
The philosopher of ardent and inventive mind, content to know 
the general proportions, is unwilling to stop his career of dis- 
covery in order to learn the minute fractional quantities ; nor will 
he suffer his whole faculties to flutter round the oscillations of a 
balance. Let none, however, hence imagine, that we desire to 
disparage quantitative research ; we would only assign it a place of 
due subordination below the qualitative, conversant with new 
powers and forms of matter. To view, with Dr. Thomson, the 
first principles of chemistry as consisting in an enumeration of 
weights and measures, is to narrow and debase the science into an 
affair of addition and subtraction. This arithmetical process is, 
no doubt, a valuable accessory ; but can never compete either in 
interest or utility with the knowledge of the chemical affinities, 
from whose play, the countless diversities of composition and un- 
ceasing successions of form in the material system, are derived. 
These are the grand principles of chemical action, an acquaint- 
ance with which must necessarily take precedence of the study of 
quantity. 

It is deeply to be lamented that the latter kind of inquiry, 
which, as exhibited in the work before us, can hardly be deemed 
an intellectual operation, should have usurped, to too great a de- 
gree, in some recent publications, the place of researches into the 
powers that modify matter. Admirable specimens of this sublime 
study are to be found in the statics of M. Berthollet, the Bake- 
rian lectures and " Elements" of Sir H. Davy, and in many memoirs 

Vol. XX. I 


114 Review of Dr. Thomson 

of M. Gay Lussac and Dr. Wollaston ; and the individual, who 
should collect and arrange these into a compendious volume, 
would do no mean service to science. Of such philosophical 
principles we can perceive no trace in Dr. Thomson's book ; 
though the modern multiplication of chemical objects, simple and 
compound, loudly demands their general connexions and depen- 
dencies to be developed. 

" An Attempt to establish the First Principles of Chemistry by 
Experiment," is the title of Dr. Thomson's book; a title which 
may be understood in two senses. First, it may seem to imply 
that the doctor modestly offers his labours as a mere attempt ; or 
secondly, that others before him might perchance have laid down 
first principles of chemistry, but that the grand sera of esta- 
blishing them by experiment, was reserved for himself. The reader 
is not left long in suspense by the ambiguity of the title ; for the 
first pages show that the latter conceit has taken possession of 
the author's mind. From the preface, indeed, one might be led to 
look for some of those Herculean achievements with which Sir 
H. Davy astonished the world in his Elements of Chemistry, 
although his title-page did not blazon them forth. But nulla fides 
fronti is an adage which the reviewer has too many reasons to 
recollect. 

We shall not, however, deal ungenerously with the Doctor ; far 
less mete out to him with his own measure. We are ready to ad- 
mit that by noting the mutually precipitating quantities of two 
neutral salts, he has in several cases given useful corrections of 
the primitive combining weights of bodies ; and that he has, on 
some occasions, shewn errors in the second, and even first, decimal 
places of numbers formerly found. But, undoubtedly, his chief 
ingenuity is displayed in concealing, throughout the details of the 
book, the previous researches on the same topics of other experi- 
menters, even when their results do not perceptibly differ from 
his own, which he presents as absolute perfection. Hence a young- 
student will be led by the perusal of Dr. Thomson's " Attempt," 
to consider it both as the commencement and completion of che- 
mistry, since he deigns to notice few precursors, and those chiefly 
for the purpose of pointing out their mistakes. He demonstrates 
his own numbers to be true, frequently to a millionth part ; and 
rarely rests satisfied with a possible error of one part in a 
thousand ! 

Nothing places in so strong a light the vast improvement of 
practical chemistry during the last thirty-five years, as a compa- 
rison of modern results on chemical equivalents, with those ob- 
tained by Richter in his Researches published in 1792, and some 
succeeding years. He mixed together two neutro-saline solutions, 
in such a proportion, as to produce their mutual decomposition, as 
indicated by the complete precipitation of the new-created com- 


on the Atomic Theory. 115 

pound. This chemical operation is very simple, and with regard 
to many substances, susceptible of very considerable precision. 
Yet Richter's equivalent numbers are so erroneous, as to shew 
that he must either have been very careless, or have employed 
very impure salts. Wenzel, a much earlier writer, and the real 
author of those general views which Richter prosecuted concern- 
ing mixed saline solutions retaining the state of neutrality or 
acidity which they previously possessed, had however made far 
more accurate researches on the composition of salts ; but these 
had been unaccountably neglected, though capable of furnishing 
excellent data for the theory of chemical equivalents. 

Fischer, in the compendious table which he constructed from 
Richter's voluminous experimental tables, states sulphuric acid at 
1000. Hence if we divide his equivalent numbers by 20, the 
quotients will shew their relation to sulphuric acid reckoned 50, 
as it is on Dr. Wollaston's scale. The following are a few of 
these quotients : 


Potash 


80 


Magnesia 


30.7 


Soda 


43 


Barytes 


111.1 


Ammonia 


33.6 


Muriatic acid 


35.6 


Nitric acid 


70 


Carbonic acid 


28.8 


Lime 


39.6 


Surely nothing but the impurity of the bodies submitted to ex- 
periment, can account for the errors in these numbers ; the three 
acids presenting the only tolerable approximations to truth. And 
indeed till chemicals could be procured in a state of purity, the 
method of research, by ascertaining the mutually precipitating 
quantities of saline matter, was quite nugatory. At the present 
day, however, the greater part of the most interesting saline com- 
pounds are prepared for sale by the manufacturer, so beautifully 
crystallized as to be quite free from impurities, and admirably 
adapted for the investigation of equivalent numbers. Such 
articles, made on the great scale by eminent dealers, are generally 
to be preferred for scientific purposes to those made in little cap- 
sules by the closet experimenter. 

When the happy idea of atomic combination was broached by 
Mr. Dalton, chemical synthesis and analysis had become much 
more exact, as his collation of results exhibits. In the first vo- 
lume of his " New System/' published in 180S, we find the fol- 
lowing numbers, reduced to oxygen 10, and sulphuric acid 50. 


Azote 


7.1 


Magnesia 


28.6 


Carbon 


7.1 


Lime 


33.0 


Phosphorus 


13.0 


Soda 


40 


Sulphur 


18.6 


Potash 


60 


Barytes 


97.1 


Nitric acid 


27.1 


The only articles here very erroneously given are azote, and its 
compound, nitric acid. Most of the other numbers do not differ 

I 2 


116 Review of Dr. Thomson 

much from the latest determinations ; while those for soda and 
potash are exact. 

Berzelius, familiar at an early period with Richter's specula- 
tions, was naturally prepared to embrace Mr. Dalton's views of 
atomic combination. He zealously set to work to determine, by 
the most refined and rigid methods of analysis, and synthesis, the 
true proportions in which chemical bodies combine. His success- 
ful labours formed the ground- work of Dr. Wollaston's valuable 
memoir on chemical equivalents. It is meanwhile worthy of re- 
mark, that Berzelius should very rarely have had recourse to 
Richter's method of mutual precipitation, in order to infer the 
atomic number of an unascertained salt, or of its constituents, 
from that of one already known. 

Dr. Thomson is the first chemist who has methodically pursued 
this very simple and obvious route. Operating with the purer 
salts of modern times, he has been enabled to rectify and define 
the atomic numbers of a good many compounds ; and thence also 
to deduce, on some occasions, the atomic weights of their consti- 
tuents. He commenced this task in the " Annals of Philosophy, 
for Nov. 1820," in which he published the atomic weights of ba- 
rytes, potash, soda, muriatic acid, protoxide of lead, sulphuric, 
nitric, and chromic acids. Of the numbers for the first four, as 
stated by Dr. Wollaston, he corrected the second decimal figure ; 
the others seem to have admitted of scarcely any alteration, for 
Dr. Thomson's numbers nearly coincided with the previous deter- 
minations of Wollaston and Berzelius. 

In verifying atomic numbers by the method of mutual saline 
precipitation, had Dr. Thomson been careful to ascertain that the 
decomposition was complete, as he might have done by suitable 
re-agents, much more confidence might have been reposed in his 
labours. But he has very frequently neglected this essential pre- 
caution, as we shall shew in the course of this examination of his 
work, and hence he has pretty often presented us with results, 
tallying well with the atomic theory, and with Berzelius, which 
he states as his own, though they could never have been derived 
from his narrated experiments. He has been also somewhat im- 
prudent in quitting the solid track of precipitation, and of trying 
by novel methods, to demonstrate the truth of the idea suggested by 
Dr. Prout, that the atomic weights of all chemical bodies are 
multiples, by a whole number, of the atomic weight, of hydrogen. 

Ceratis ope Dcedalea 
Nitilur pennis. 

The ingenious author of that proposition adduced so many exam- 
ples, and analogies, as to render it highly interesting and plausible ; 
and it has accordingly been regarded with a partial eye by the 
most eminent of our chemical philosophers. The beautiful law 
of gaseous combinations, discovered by M. Gay Lussac, and their 


on the Atomic Theory. 117 

densities to that of hydrogen being apparently in simple arith- 
metical proportion, naturally pointed to the principle so ably de- 
veloped by Dr. Prout. 

The proportion of the two elements in the composition of water, 
is by common consent regarded as constituting the ground-work 
of the atomic scale. Water is known to consist of one volume of 
hydrogen combined with half a volume of oxygen ; and if this 
half volume be exactly eight times heavier than the entire volume 
of hydrogen, we shall have their atomic relation represented by 
these numbers. This half volume of oxygen, viewed as a com- 
ponent of concrete bodies, is estimated to weigh 1 ; phosphorus 
then weighs 1.5, and sulphur 2. But if that half volume of 
oxygen be contemplated in its gaseous state with reference to one 
volume of air as 1, or unity, its weight becomes 0.5555 ; and 
the atomic weights of the other bodies are brought into com- 
parison with this gaseous standard, by reducing their atomic 
numbers in the ratio of 1.0000 to 0.5555. Thus phosphorus will 
become in the primitive combining volume of its vapour, 
0.833 = 1.5 X 0.5555; and sulphur, 1.1111 s= 2X0.5555. 

In some cases, the concrete aspect of the oxygen atom, or 
prime equivalent =1, is convenient; in others, the gaseous as- 
pect z= 0.5555. They are, however, merely different forms of the 
same proposition ; nor can the arithmetical reduction of the 
concrete unity to the pneumatic expression, be considered, with 
Dr. Thomson, as a law of combination. In fact, the assumption 
that half a volume of oxygen constitutes one atom, versus an 
entire volume of hydrogen, is altogether arbitrary, and merely a 
matter of convention among chemists. 

We are acquainted with no body, contemplated in its gaseous 
state, which unites with less than its own volume of hydrogen. 
Most bodies, on the contrary, which combine with hydrogen, do 
so in the same proportion as oxygen does ; that is, they take 
twice their volume of this inflammable gas. Now, if the densities 
of hydrogen and oxygen gases are as 1 to 1 6 exactly, then from the 
known relations of oxygen to other bodies, it will not be difficult 
to shew, that their atomic weights will be all, very nearly, if not 
exactly, whole numbers, or multiples of hydrogen = 1. Thus 
we perceive carbon to be 6, oxygen 8, phosphorus 12, nitrogen 14, 
sulphur 16, &c. 

Dr. Thomson, in his " Historical Introduction," considers 
Mr. Dalton's choice of the atom of hydrogen for unity, as un- 
happy ; asserting, that with the exception of Dr. Henry, of Man- 
chester, and one or two chemical gentlemen in London, " this 
method has been rejected by almost all the British chemists, and 
by all the chemists without exception in Europe and America." 
The Doctor's reasons are thus stated: " 1. Because the atom of 
nydrogen is the most difficult of all to determine ; and chemists 


118 Review of Dr. Thomson 

are not yet all agreed about its weight. 2. Hydrogen, so far as 
we know at present, combines with but few of the other simple 
bodies ; while oxygen unites with them all, and often in various 
proportions. Consequently, very little advantage is gained by 
representing the atom of hydrogen by unity ; but a very great 
one, by representing the atom of oxygen by unity. For it re- 
duces the greater number of arithmetical operations respecting 
these bodies to the addition of unity ; and we see at once, by a 
glance of the eye, the number of atoms of oxygen which enter 
into combination with the various bodies. Thus, if the atom of 
manganese be represented by 3.5, and the weight of the various 
oxides of that metal be as follows : 

1. Suboxide 4 4. Tritoxide 5.5 

2. Protoxide 4.5 5. Manganesious acid 6.5 

3. Deutoxide 5 6. Manganesic acid 7.5 
It is obvious at once tfcat the 

Suboxide contains J atom ox. Tritoxide 2 atom ox. 

Proxide 1 Manganesious acid 3 

Deutoxide lj Mangenesic acid 4 

Whereas, if we were to make the atom of hydrogen unity, 
these weights would be as follows : 

Manganese 28 Tritoxide 48 

Suboxide 32 Manganesious acid 56 

Protoxide 36 Manganesic acid 64 

Deutoxide 40 

Numbers, which would not suggest the number of atoms of 
oxygen contained in each, with the same facility *." 

The first reason given by Dr. Thomson applies with equal 
force to oxygen, for its relation in atomic weight to other bodies 
is little better known than that of hydrogen to them. The pro- 
portional weights of these rival elements are always inferred 
from the composition of water ; and whatever relation be dis- 
covered between them, it will pervade the whole system of 
bodies which have for a constituent either hydrogen or water. 
In Mr. Dalton's original numbers, published in 1808, the atomic 
relation of hydrogen to oxygen in water is 1 to 7 ; and therefore 
to reduce all the numbers to the oxygen unity, they have only to 
be divided by 7. No error will be introduced into the resulting 
numbers, by having taken the hydrogen unity, provided the 
analyses of the oxides and oxygen acids have been exact. Again, 
if water be supposed to consist of 1 part hydrogen to 7\ oxygen, 
as on Dr. Wollaston's scale, surely this synoptic table would not 
have its accuracy affected by reducing the numbers to a hydro- 
gen unity ; for the relations of oxygen to the other bodies, 
being deduced from their proper authorities, would stand as 
before. 

* Historical Introduction, p. 14. 


on the Atomic Theory, 119 

Hence it is obvious that the system of atomic weights derives 
no immunity from error, by calling oxygen 1, and hydrogen 
0.125. The following manifesto of Dr. Thomson is therefore 
founded on a false conception ; " whereas, if we make choice of 
oxygen for our unity, any error respecting the atom of hydrogen 
will be confined to that atom, and will not affect the accuracy of 
the atomic weights of other bodies*." On the contrary, an 
error respecting the hydrogen atom will affect the atomic num- 
bers of all the hydrogen acids and hydrates, under which title 
rank most of the free acids, a great proportion of the salts, and 
all the organic products. 

The second reason assigned by Dr. Thomson, that hydrogen 
combines with but few of the other simple bodies, is a very sin- 
gular one ; for hydrogen forms a variety of most interesting 
compounds with all the simple bodies non-metallic, as also with 
some metals, while its compound, water, is of almost universal 
agency. 

Three advantages accrue from the assumption of hydrogen, as 
the atomic unity. 1 . We get rid of numbers less than unity in 
the scale of equivalents. 2. We avoid fractional quantities 
throughout the whole range of atomic numbers. 3. The atomic 
numbers in the hydrogen scheme, exhibit for the most part in 
reference to that gas, the specific gravities of the chemical 
bodies supposed to be in the aeriform state ; and the combining 
ratios of their weights, under the same volume, are made manifest 
to the eye. This is a capital advantage in all researches on the 
gases, or on bodies which afford gaseous products in analysis. 
Let us consider this proposition, in reference to a few leading 
chemical bodies, Carbon, Phosphorus, Azote, and Sulphur. 

1. Subcarburetted hydrogen gas is, as its name indicates, a 
compound of one volume vapour of carbon + 2 volumes of 
hydrogen gas ; the weight of which are 6 + 2 = 8; which 
sum, from the 3 volumes being condensed into 1, is its specific 
gravity, compared to hydrogen = 1 . 

2. Carburetted hydrogen or olefiant gas. A volume of this 
compound consists of 2 volumes hydrogen + 2 volumes carbon, 
whose weights are § -f- 13 =14; and as these 4 volumes be- 
come 1 volume of the compound gas, the specific gravity of this 
will be 14, if hydrogen is 1. 

3. Phosphuretted hydrogen results from 1 volume of phos- 
phorus as 12 + 1 of hydrogen = 1, constituting 1 volume, 
whose weight is 13, being the specific gravity, as well as atomic 
weight, of the aeriform compound on the hydrogen scale. 

4. Subphosphuretted hydrogen is composed of 1 of phosphorus 
= 12 + 2 hydrogen = 2, constituting 1 volume, whose weight 
is 1 4. This is at once the atom ana the density. 

* Historical Introduction. 


120 Review of Dr. Thomson 

5. Hydrogen with azote, or ammonia. This compound con- 
sists of 1 azote =14 + 3 hydrogen =s 3, whose joint weight is 
7 ; and as these 4 volumes compose 2 of ammonia, the resulting 
specific gravity will be y = 8j times that of hydrogen. The 
specific gravity becomes here one-half of the atomic weight. 

6. Hydrogen with azote and carbon ; the prussic, or hydro- 
cyanic acid. This body consists of 2 carbon = 12, + 1 azote = 
14, + 1 hydrogen = 1, whose sum is 27; which 4 volumes 
together constitute 2 ; therefore the specific gravity is %f = 131 
times that of hydrogen ; while the atom is the double. 

7. Cyanogen, or bicarburet of azote. It consists of 2 carbon 
= 12, +1 azote =14, whose sum is 26; and as these 3 vo- 
lumes form 1, its specific gravity will be 26 times that of hy- 
drogen. 

8. Sulphuretted hydrogen. This is composed of 1 sulphur = 
16, + 1 hydrogen = 1, whose sum = 17, is the specific gravity 
of the gas compared to hydrogen, for the hydrogen does not 
change its volume in combining with the sulphur ; or a volume 
of hydrogen gas and one of vapour of sulphur compose one volume 
of sulphuretted hydrogen gas. 

When oxygen is contemplated in the general relations of 
weight and volume to hydrogen, we must bear in mind the 
hypothetical assumption at the root of both schemes of equivalent 
numbers ; viz., that half a volume of oxygen = 8 is the primi- 
tive combining proportion. If we regard water as consisting of 
2 volumes of hydrogen + 1 of oxygen, the entire volume of 
oxygen becomes 16, and therefore we shall have 2 + 16 = 18 
for the total weights ; and as these 3 volumes of constituents 
form 2 volumes of aqueous vapour at 212° Fahr., we shall have 
its density L8 = g ? an( j if hydrogen be called 0.0694 in reference 
to air = 1, the vapour will become 0.625 = 9 X 0.06944. 
As the density is here compared to air of the same temperature, 
the relation of 0.625 to 1 will continue through the thermometric 
range, since vapours out of contact of their liquids, and gases, 
suffer the same change of volume by change of temperature. 
The diminished specific gravity of the vapour will be therefore 
simply proportional to its diminished tension or elastic force. 

The preceding exemplification of the value of the hydrogen 
radix, will we trust satisfy our readers, that Dr. Thomson must 
have formed a somewhat crude conception of chemical equiva- 
lents, when he talks so slightingly of that atomic scale. He 
should reserve his dogmatic decisions for more tangible matters. 
In a word, let any practical man compare the hydrogen and 
oxygen scales in reference to the water of crystallization of salts, 
and he will readily find that 9 and its multiples, are much more 
manageable than the multiples of 1.125. 

But the Doctor is not content with reasoning alone ; he must 
needs exemplify, and his manganese case is a droll enough proof 


on the Atomic Theory, 121 

of the very great benefit (to himself) " of representing the atom 
of oxygen by unity, for it reduces the greater number of arith- 
metical operations, respecting these bodies, to the addition of 
unity." When a gentleman's arithmetic extends no farther than 
the addition of unity, assuredly Dr. Thomson's plan is the only 
safe one ; and he illustrates with peculiar naivete the intricacy of 
the other plan, in which hydrogen being called 1, oxygen assumes 
the formidable magnitude of 8. On multiplying the following 
quantities of his favourite scale, viz., 3.5, 4, 4.5, 5, 5.5, 6.5, 
and 7.5, by that unwieldy number 8, he has committed 3 blun- 
ders \ his products being, as we have quoted them above, 

28 1 f 28 S= 


32 
36 
40 
48 
56 
64 


instead of 


28 ss 3.5 


X 8 


32 5= 4 


X 8 


36 s± 4.5 


X 8 


40 es 5. 


X 8 


44 = 5.5 


X 8 


52 s= 6.5 


X 8 


60 = 7.5 


X 8 


"We shall no longer be surprised at Dr. Thomson's antipathy 
to the hydrogen scale ; though to a student somewhat advanced 
in simple addition or multiplication, a short succession of 8's will 
not be found very difficult to link together. Were we anxious 
to rest our cause on the authority of names, as Dr. Thomson has 
tried to do, we would adduce as its patrons, Sir H. Davy, Mr. 
Dalton, Dr. Prout*, Dr. Henry, Mr. R. Phillips, and many 
other chemists, who prefer the hydrogen to the oxygen radix. 
Since the atomic theory is an indigenous plant, whose habitudes 
and cultivation have been but partially studied abroad, we can- 
not allow to the opinions of continental chemists much weight in 
the discussion. 

We shall pass over, without further remark, Dr. Thomson's 
Historical Introduction, as also his Second Chapter, entitled, 
" Of the Atomic Theory," as presenting nothing of interest. 
Having got mystified, to no purpose, among the canons of 
Dalton and Berzelius, he strives to emerge, by a rank and file 
parade of acids, with 3 atoms of oxygen, with 1 atom, with 2, 
4, 5, 7, and 8 ; an arrangement turned to no subsequent account. 

His Third Chapter, u On the Specific Gravities of Oxygen and 
Hydrogen Gases," is held forth as M the key-stone of the build- 
ing," and therefore it merits our especial attention. It is divided 
into three Sections, the first of which treats of the composition of 

* There is an advantage in considering the volume of hydrogen equal to 
the atom, as in this case the specific gravities of most or perhaps all ele- 
mentary substances (hydrogen being 1) will either exactly coincide with, or 
be some multiple of the weights of their atoms," &c— Dr. Prout in Ann. of 
Phil. vii. 113. 


122 Review of Dr. Thomson 

oxide of zinc ; the second, of the specific gravity of oxygen gas ; 
and the third of that of hydrogen gas . 

He sublimes ordinary zinc in an earthen retort, dissolves a 
given weight of it in nitric acid, and then expels the acid, by 
heating the nitrate to redness in a green glass retort. In this 
way, he obtains at once, to the minutest fraction, every thing 
which Dr. Prout's atomic multiples require, viz., 5.25 grains of 
oxide, from 4.25 grains of metal. This felicity of coincidence 
between his experiments and his theoretical aim is so usual with 
Dr. Thomson, and with him alone, as to excite no surprise in our 
minds. Another chemist, in quest of final precision, would have 
procured his zinc by reviving the metal from a pure carbonate, 
precipitated from a well crystallized sulphate ; as he would know 
that it is impossible to obtain pure zinc by subliming the metal 
of commerce. Proust long ago sought to determine the com- 
position of oxide of zinc in the above way. He obtained 125 
grains of oxide, by igniting the nitrate formed from 100 grains of 
metal. This made its atomic weight 4 ; and it is probable that no 
chemist could get the number 4.25 by oxidizing zinc purified by 
sublimation alone, as it usually contains arsenic, cadmium, &c, 
which rise along with it. 

We by no means assert that the atomic weight of zinc is not 
4.25, for this is the mean number deducible from the experiments 
of Sir H. Davy, and M. Gay Lussac ; and it is a number Dr. Thom- 
son contrives to obtain in another, but very complicated, way. 
His atomic certainty of result springs out of the following ope- 
rations. He decomposes a given weight of sulphate of zinc by 
carbonate of soda, he washes this carbonate on a nitre, dries it, 
and finally exposes it to a red heat. After these manipulations, 
Dr. T. gets his experimental weight to tally with his theoretic 
wishes, to the third decimal figure ; a comfort rarely enjoyed by 
other practical chemists. In the last edition of his System of 
Chemistry, crystallized sulphate of zinc is declared to hold 5 
atoms of water; 7 are now recognised, being 2 more than Ber- 
zelius and some other inquirers met with. We believe, indeed, 
that the Doctor's salts have been often in a peculiar state, as to 
their water of crystallization. 

In the section on the specific gravity of oxygen gas, he has the 
hardihood to refer to his experimental results, published in the 
sixteenth volume of the Annals of Philosophy, as being perfectly 
accurate, though it has been fully demonstrated, that they were 
wide of the truth *. What renders this reference peculiarly ab- 
surd, is, that in the present book he abandons the notions he 
formerly held, on the weight of moisture existing in a gas stand- 
ing over water, and adopts a formula for ascertaining its amount, 

* See Quarterly Journal of Science for June, 1822. 


on the Atomic Theory. 123 

which, though still inexact, yet being applied to his former expe- 
riments, throws them all beyond the pale of the atomic theory. 
To square his experiments with Dr. Prout's numbers, he, on that 
occasion, estimated the weight of aqueous vapour in his gases, 
at about one-sixtieth of what they really contained; and now, 
when he admits that there must be nearly fifty times more mois- 
ture in them, still he cites his old results as true. His new ideas 
relative to aqueous vapour, we shall presently discuss. Meanwhile, 
let us consider " the attempts which he has made to determine 
the specific gravity of oxygen gas in quite a different way." 

He dissolved in dilute sulphuric acid, 100 grains of distilled 
zinc, contained in a small glass retort. At the end of twenty-four 
hours, the metal being dissolved, and the apparatus, <§-c, having 
taken the temperature of the room, he obtained in each of 2 ex- 
periments, a volume of moist hydrogen gas, which, reduced by 
calculation, gave at 60° Fahr., 138.755 cubic inches. He con- 
cludes, that one half of this volume or 69.3775 cubic inches of 
oxygen gas, have entered into union with the zinc. But from his 
researches in the preceding section, it appears, " that 100 grains 
of zinc when converted into an oxide, combine with 23.5294 grains 
of oxygen. Hence, the weight of 69.3775 cubic inches of oxygen 
gas, is 23.5294 grains. Consequently, 100 cubic inches weigh 
33.9 15 grains *. Estimating with Sir George Shuckburgh Evelyn, 
the weight of 100 cubic inches of dry air to be 30.5. grains, the 
specific gravity of oxygen comes out 1.1111, or Dr. Prout's theo- 
retic number exactly. This concurrence of numbers, in the sequel 
of such experiments, we may venture to predict will hardly be 
realized by any other chemist. 

Having settled this point to his entire satisfaction, he con- 
cludes the section by a formula, to shew what influence the pre- 
sence of moisture must exercise on the specific gravity of oxygen 
gas. But his formula is rendered altogether erroneous by his 
adopting 0.00772, as the specific gravity of aqueous vapour at 
60° Fahr. This being a matter of fundamental importance in 
pneumatic chemistry, and one much misunderstood, we shall de- 
vote a paragraph or two to its elucidation. 

M. de Saussure took extreme pains to determine, by direct ex- 
periment, the weight of aqueous vapour contained in a given por- 
tion of moist air. He ascertained that the same volume of dif- 
ferent gases, standing over water at a given temperature, afford, 
on being dried by muriate of lime, the same weight of water ; 
which, for 100 cubic inches of aeriform matter, amounted to 0.35 
of a grain. Now the subsequent researches of M. Gay Lussac, 
and Mr. Dalton, concur to shew that the same volume and weight 

* Thomson's First Principles, i. 65. Taking his own data, the above num- 
ber comes out 69.S765, but this error is of no consequence. 


124 Review of Dr. Thomson 

of aqueous vapour exists in moist air, as would be found, at the 
same temperature, in a vacuum of the same capacity. Thus, 100 
cubic inches of moist air, at 60°, will contain 100 cubic inches of 
aqueous vapour at 60° ; which, by Saussure's experiments, weigh 
0.35 grain. Dividing this number by 30.5, the weight of 100 
cubic inches of dry air, the quotient 0.0114 will be the specific 
gravity of vapour at 60°, referred to air as unity. 

According to M. Gay Lussac, the specific gravity of steam at 
212° is to air at 212°, under the barometer pressure of 30 inches, 
as 0.625 to 1.000. But vapours out of contact of liquids, and 
air, follow the same rate of expansion or contraction, by change 
of temperature. This ratio of 0.625 to 1.000, holds therefore at 
all temperatures ; and we have therefore merely to estimate the 
diminution of the quantity of vapour, due to its diminished ten- 
sion. Now from the latest table of elastic forces of steam, that 
published in the Philosophical Transactions for 1818, we learn 
that the tension at 60° is represented by 0.516 of an inch of 
mercury ; and consequently, that the weight of vapour is dimi- 
nished in the ratio of 0.516 to 30 inches. But °' 625 X ?' 516 = 

30 

0.01075 ; which is the specific gravity of aqueous vapour at 60o 
Fahr. ; and 100 cubic inches of it will weigh 0.327875 == 30.5 
X 0.01075, or pretty nearly one-third of a grain. 

Gay Lussac has also shewn that aqueous vapour, at any tem- 
perature and pressure, consists of a volume of hydrogen, + half 
a volume of oxygen, constituting together one volume. Now a 
volume of hydrogen, therm. 60°, and barometric pressure 0.516, 

• ^^/mi«o 0.0694 X 0.516 , , ir , r 

is 0.001193 sr ; and halt a volume of oxygen 

. ., . a -*m»*i>* 0.5555x0.516 riM. - 

m the same state is 0.009555 = . The sum of 

30 

these two quotients is 0.01075 ; precisely as deduced above, in 
a different manner. 

One hundred cubic inches of air, barom. 30, standing 
over water at 60° Fahr., consist of 100 cubic inches of dry air 
supporting a barometric pressure of 29.484 inches of mercury, 
and 100 cubic inches of vapour, sustaining a pressure of 0.516 of 
an inch of mercury. But 100 cubic inches of dry air, under that 
pressure, weigh 29.9754 grains, and 100 cubic inches of vapour 
under its pressure weigh 0.3278 grains. The sum 30.3032 is the 
weight of the hundred cubic inches of moist air, sustaining the 
total pressure of 30 inches of mercury. 

In like manner, 100 cubic inches of oxygen gas standing over 
water, at 60° Fahr., consist of 100 cubic inches, sustaining a 
pressure of 29.484 inches of mercury, and 100 cubic inches of 


on the Atomic Theory. 125 

aqueous vapour, bearing the remaining portion of the pressure = 
0.516 of an inch ; 100 cubic inches of such oxygen weigh 33.88 x 
0.9828 ss 33.3047 + 0.3278 vapour. The sum 33.6325 is there- 
fore the weight of 100 cubic inches of oxygen standing over 
water at 60°, barom. 30. Its specific gravity, compared to moist 
air, or their relative weights, when taken by the same balloon 

33 6325 

and balance at the same time, will be . = 1.10986. But 

30.3032 

Dr. Thomson's wonder-working balance afforded him directly, in 
these circumstances, the specific gravity 1.1117, being Dr. Prout's 
theoretic number, where that number ought not to be found. 
Such a fictitious, or we might rather say, factitious coincidence 
destroys all confidence in Dr. Thomson's experiments on the spe- 
cific gravity of the gases. 

The above calculation may be represented by the following 
formula, calling S, the specific gravity of dry gas, (bar. 30, and 
therm. 60°) ; v, that of vapour at 60°;/, its elastic force ; then 
the specific gravity of the gas standing over water, bar. and 

30 — / ' -4- v 
therm, as above, will be S X ^—- 

03 

We have seen that a volume of such moist gas consists of a 

volume of dry gas, supporting — ! of the atmospheric pres- 
sure -f a volume of vapour supporting — ! of that pressure. 

Hence, by deducting from the specific gravity of the moist gases 
the weight of the volume of vapour present, or its specific gra- 
vity 0.01075, the remainder will be the specific gravity of the 
dry gases, under a barometric pressure of 29.484 inches. Thus 
the following tabular view arises. Specific gravity of 

Dry at 30 Bar. Dry at 29.484 B. Vapour at 60*. Moist air at 60*. 

Air . 1.00000 0.98280 + 0.01075 = 0.99355 

Chlorine 2.50000 2.457 + 0.01075 = 2.46775 

Oxygen 1.11111 1.09199 + 0.01075 tea 1.10274 

Hydrogen 0.06944 0.06825 + 0.01075 tec 0.07900 

If moist air be called unity, then the specific gravities of the 
other gases standing over water will be 

Chlorine . . . 2.48370 

Oxygen . . . 1.10986 

Hydrogen . . . 0.7951 

In moist oxygen gas, the aqueous vapour fonns only T ^ of the 
total weight ; but in moist hydrogen, it constitutes more than \. 

Many readers will probably complain of the prolixity of this de- 
velopement of the influence of moisture on the specific gravity of 


126 Review of Dr. Thomson 

the gases. But as Dr. Thomson, and some other chemists of 
name, have propagated incorrect ideas on the subject, we felt it 
our duty to rectify them. We shall presently apply these plain 
enough propositions to the Doctor's new researches, when a 
comical conflict will be seen, between experiment in masquerade, 
and a pattern theory. In his anxiety to monopolize the honour 
of finishing the fabric of Dr. Prout, our author has, unhappily for 
his fame, deranged the whole edifice, and instead of fixing the 
key-stone, has actually laboured unwittingly to displace it. 

In order to ascertain the weight of a given volume of hydrogen 
gas, he dissolved a certain weight of zinc in dilute sulphuric acid, 
contained in a matrass, to whose orifice there was luted a glass 
tube, filled with dry muriate of lime. The quantity of his zinc 
" was unluckily very much limited by the small size of the flask," 
whence the temperature of the mixture was less uniform, and 
the heat of the effluent moist gas proportionately uncertain ; for 
in one experiment, it rose from 50° to 87°, and in another from 
48° to Sl°, when the flask stood in the air. In subsequent expe- 
riments, therefore, he surrounded the flask with water at 48°, 
but as he did not insert the bulb of a thermometer into the ma- 
trass, the temperature of its interior was unknown, and conse- 
quently that of the gas disengaged. 

On repeating Dr. Thomson's experiment, we have found that 
the interior thermometer stood very considerably above that of 
the exterior one, whose bulb was near the vessel, or even in con- 
tact with it ; and that, probably, the temperature of the effluent 
gas may be estimated at about 1 1 or 1 2° above that of the water- 
bath surrounding the flask. 

When 100 grains of zinc were dissolved, " the loss of weight 
sustained by the flask was 3 grains, and the tube containing the 
muriate of lime had increased in weight 0.1G3 of a grain*." 
From former experiments, he found that 100 grains of zinc af- 
forded, during their solution in dilute acid, 136.88 cubic inches of 
hydrogen gas, bar. 30.1, therm. 49°. "The specific gravity of 
vapour at 49°, under a pressure of 30.1 inches of mercury, is 
0.00533 ; and the weight of the vapour, contained in 136.88 cubic 
inches of moist gas, is 0.0533 X 136.88 X 0.305 gr. = 0.2225 
grain ; but the moisture retained by the muriate of lime was only 
0.163 gr. It is obvious from this, that the hydrogen still re- 
tained 0.059 of a grain." 

" If from the weight lost, amounting to 3 grains, we subtract 
this 0.059 grain for moisture, the remainder, amounting to 2.941 
grains, gives the true weight of the hydrogen gas exhaled, sup- 
posing it perfectly dry. Now, from the experiments related in 
the last section, we know that the volume of this gas, under the 

* Thomson'' s Attempt, i. 69. 


on the Atomic Theory. 127 

pressure of 30 inches of mercury, and at the temperature of 60°, 
is 138.7551 cubic inches *." 

There is an astounding fatuity in this passage. The flask loses 
3 grains in weight; of this loss, he calculates that 0.2225 is due 
to moisture vaporized in the hydrogen. Hence, 3 — 0.2225 
= 2.7775 is the weight of the dry hydrogen, by his own shew- 
ing. The fractional quantity 0.059 is merely the moisture, which, 
by his account, escaped the hygrometric action of the muriate of 
lime, which quantity + that in the muriate of lime = 0.2225 falls 
to be deducted from the loss of weight in the flask = 3 grains. 4 
And what is the drift of this novel experiment ? Do its results 
shew the weight of a given bulk of hydrogen, in a definite state of 
moisture or dryness ? Certainly not. For, though his purpose 
was to determine experimentally the proportion of dry air and 
moisture in a known volume of the moist gas, he is obliged to 
have recourse to calculation, to learn that proportion. But as he 
does not know the temperature of the effluent hydrogen, he wants 
the essential datum of that calculation. And supposing that by a 
wiser disposition of the experiment, he had known this datum, 
still his result would have been wrong, because the specific gra- 
vity of aqueous vapour is very different from what he assumes it 
to be in his formula. The confusion of thought, discovered by the 
Doctor on the present occasion, can only be accounted for on the 
supposition, that his head got turned in planting, as he fondly 
fancied, " the key-stone" of the grand atomic arch. We do not 
consider the experiment susceptible of remarkable precision in 
the best hands ; but at any rate it might be made a rational, if it 
cannot be made a delicate one, by causing the disengaged gas to 
traverse a convoluted glass tube, surrounded by melting ice. The 
hydrogen would then escape in a definite hygrometric state, and 
its weight would be exactly known from the loss of weight suf- 
fered by the apparatus. 

He concludes as follows: — "Thus it appears that 138.7551 
cubic inches of dry hydrogen gas (bar. 30 inches, therm. 60°) 
weigh 2.941 grains; consequently 100 cubic inches must weigh 
2.119 grains. " 

On the contrary, the weight of that bulk of his dry hydrogen is, 
by his own statement, 2.778 grains, and therefore the weight of 
100 cubic inches is 2.77S divided by 1.387551 = 2.002. 

" But we have seen in the last section that 100 cubic inches of 
oxygen gas weigh 33.915 grains ; now 

2.119 : 33.915 :: 1 - 16.005. 
" This approaches so nearly the ratio of 1 : 16, that it leaves 
no doubt that the specific gravity of oxygen gas is exactly 16 
times greater than that of hydrogen gast." 

It is truly fatiguing to wade through such an inundation of 

* T/iomson's Attempt, i. ^0. r Ibid. i< 71. 


128 Revieio of Dr. Thomson 

blunders. His own result, in reality, gives 2.002 grains for the 
weight of 100 cubic inches of dry hydrogen (bar. 30, therm. 60°), 
whence the following proportion : — 2.002 : 33.915 : 1 : 16.9, a 
number which, if true, would utterly subvert Dr. Prout's theory. 

But it is time to return to his estimate of the specific gravity of 
vapour at 49° bar. 30.1. He states it, most erroneously, at 
0.00533. Let us take (as he does) Mr. Dalton's number, 0.363, 
for the elastic force of aqueous vapour at 49° Fahr. Now, the 
true specific gravity of such vapour, according to the principles 

so clearly established above, is 0.0075625 s= — - ' air 

30 

at 49° = 1.000000. But in reference to air at 60° = 1, the num- 
ber becomes 0.00773 ; for the density of air at 49° is to that at 
60° as 508 : 497 ; whence we have this proportion : 
497 : 508 :: 0. 0075625 : 0.00773. 
Hence the weight of moisture in his 136. 8S cubic inches (or 3 
grains) of hydrogen gas is 0.00773 X 136.8S x 0.305 gr. = 0.3227. 
But the muriate of lime intercepted (he says) 0.163 gr. ; therefore 
0.3227 — 0.163 — 0.1597 of a grain must have remained in the 
hydrogen, assuming his experiment to have been accurately made. 
Thus we see that about one-half of the moisture escaped the ac- 
tion of the calcareous muriate, so that its presence merely com- 
plicated the result. Deducting from 3 grains, which is the whole 
weight of humid hydrogen disengaged from the flask, the 0.3227 
of a grain of aqueous vapour, we have a remainder of 2.6773 
grains, for the weight of dry hydrogen, whose bulk, he says, 
would have been at 60° Fahr., 138.7551 cubic inches. Hence 

2 6773 

~r-^ = 1.9295. This, therefore, is the weight of 100 cubic 

1.387551 

inches of dry hydrogen, by Dr. Thomson's experiments at 30 
bar, and 60° therm. And J. 9295 : 33.915 :: 1 : 17.57. " This 
approaches (not) so nearly the ratio of 1 : 16, as to leave no 
doubt that the specific gravity of oxygen gas is exactly 16 times 
greater than that of hydrogen gas." Consequently, the specific 

gravity of hydrogen gas is— = 0.0632 ; a very different re- 

17.57 

suit indeed " from the specific gravity already deduced by Dr. 
Prout (0.0694), and which I obtained experimentally, as may be 
seen in my paper on the specific gravity of gases*." 

Of the result to which he here refers, and which is given in the 
16th volume of his Annals, p. 168, it is sufficient to say, that he 
found the specific gravity of moist hydrogen, compared to that of 
moist air, to be by experiment as 0.0694 to 1.000 1, though Dr. 

* Thomson? s Attempt, i. 71. 

t The Doctor's estimate of the equation for vapour being- about j^j of the 
real quantity, he accommodated his experiment to this fallacious judgment ! 


on the Atomic Theory. 129 

Prout's theory, whose truth he was labouring (most unskilfully, 
it must be owned) to demonstrate, requires the experimental 
specific gravity of moist hydrogen to be to that of moist air, as 
0.07951 to 1.00000, a proportion very wide indeed of Dr. 
Thomson's result. For, if hydrogen gas, standing over water, be 
not to air standing over water, both at 60°, as 0.07951 to 1.0000, 
then dry hydrogen gas will not be to dry air as 0.0694 to 1.0000. 

We are really ashamed of the necessity for such multiform details , 
but the Doctor so unblushingly foists on the public his old battered 
brass as genuine current coin, that we were here forced to call the 
tilting hammer to our aid. 

*' The key- stone of the building" being removed by his own 
hands, we shall have little further to do with the rest of his pile, 
than to keep out of the way of the rubbish. But the real atomic 
theory will not be injured by his debris. Has Dr. Thomson yet to 
learn that he is not the architect of that edifice, but a very com- 
mon labourer in the quarry ? and that its symmetry and solidity 
are equally independent of his puny efforts ? 

The fundamental proposition, that oxygen and hydrogen are to 
each other by weight, in the composition of water, as 8 to 1 ; and 
that hence the other chemical bodies may be found, in their atomic 
numbers, multiples of that for hydrogen, had been demonstrated 
by Berzelius and Dulong, two of the most accurate experimenters 
of the age. By transmitting dry hydrogen gas over black 
oxide of copper, ignited in a tube, and collecting the water pro- 
duced ; they found, on comparing its weight with the loss of 
weight sustained by the oxide, that the ratio of the hydrogen to 
the oxygen in water was 1 to 8.009 ; and since water consists of 
two volumes of hydrogen + one of oxygen, the relation of their 
densities is, as nearly as can be, -j\ ; whence calling the specific 
gravity of oxygen 1.1111, that of hydrogen becomes 0.0G94. 

There is a note to the 72d page of the Attempt, which might 
puzzle posterity. He states that the weight of his famous flask, 
filled with the dilute sulphuric acid and zinc, was about 3000 
grains. Yet, a few pages before, he tells us that " the capacity 
of the flask was about IS cubic inches, " and that it " was nearly 
filled with a mixture of sulphuric acid and distilled water, in the 
proportion of about four parts of the latter to one of the former." 
Now " about 18 cubic inches" of such acid, must weigh fully 
5000 grains, and the glass flask itself, of this size, would pro- 
bably weigh about 2000 more. Hence, with the zinc, its total 
weight must have b»en at least twice 3000 grains. Or again, if 
we take his weight, 3000 gr. versus his bulk of 1 8 inches, then 
the contents (making an allowance of only 1000 gr. for his 
glass) could not have exceeded 7 cubic inches. Is the experiment 
of the flask altogether a fable, as these palpable contradictions 
about its weight and capacity seem to indicate ? 

Vol. XX. K 


130 Review of Dr. Thomson 

Dr. Thomson's 4th chapter, on the atomic weights and specific 
gravities of chlorine and iodine, is remarkable only for dogmatical 
pretension, and eulogiums of experiments of which he should be 
ashamed. Thus, he refers to his specific gravity of chlorine gas, 
given in the 16th volume of the Annals^ because he brought out 
the number 2.5, so as to tally with Dr. Prout's theory, though 
the gas, being saturated with humidity, should have had, experi- 
mentally, the specific gravity of 2.4837, compared to moist air, 
1.000. Then, indeed, the chlorine in its dry state would be to dry 
air as 2.5 : 1.0. This trick of obtaining the atomic multiple num- 
bers, in circumstances where they cannot be found, reminds us of 
a star-gazer, who, furnished with a little quadrant, took it in his 
head to verify and correct the zenith distances of the stars. Dis- 
daining the equations for refraction, nutation, aberration, &c, he 
contrived, however, to make his results come very near to the 
places given by Dr. Maskelyne, and hence was looked up to by his 
little coterie as a great astronomer. 

We shall here introduce an example of Dr. Thomson's experi- 
mental reductions, on a very simple matter. " I find that at the 
temperature of 69°, one cubic inch of water is capable of absorb- 
ing 417.822 cubic inches of muriatic acid gas. The temperature 
of the liquid augments considerably, and its volume, when cooled 
down to the temperature of the air, is 1.3433 cubic inch. It is 
obvious from this, that 100 grains of acid of this strength contain 
103 cubic inches of acid gas ; and a cubic inch of this acid contains 
311.04146 cubic inches of acid gas. Acid of this strength has a 
specific gravity of 1.1958, and I find, by saturating it with calca- 
reous spar, that it contains 40-39 per cent, of real acid, united 
with 59.61 of water. In winter, 1 have obtained muriatic acid 
of as high a specific gravity as 1.212.*" 

In this congeries of blunders, it is hard to say whether his expe- 
riments or calculations be most in fault. 

The specific gravity of muriatic acid gas is rated by him at 
1.28472. 

1. The weight of a cubic inch of water + 417.822 cubic inches 
of muriatic acid gas is 252.5 gr. water + 163.72 gr. gas =s 416.22 
gr. of liquid acid; and 416.22 : 163.72 :*. 100 : 39.53. 

Thus 100 grains of this liquid acid manifestly contain 39.33 
grains of acid gas, and not 40.39, as he asserts. 

2. 416.22 grains of water occupy a volume = 1.6484 of a 
cubic inch ; but he tells us that the 416.22 gr. of liquid acid have 
a volume = 1.3433 cub. inch. Hence the specific gravity of the 

liquid acid is 1.227 = L6484 But Dr. Thomson asserts that 
1.3433. 

it was 1.1958, an incompatibility which we leave him to reconcile. 

* Attempt. Dr. Thomson may find a manufacturer of muriatic acid in 
Glasgow, who will supply him in winter with acid at 1.220. 


on the Atomic Theory* 131 

S. If the water bulk of the above weight of acid be divided by 
Dr. Thomson's specific gravity of the acid, we shall have its vo 

lume. Thus, — — . — ±S 1.379 cubic inch = 348.1975 grain mea- 
1.1958 & 

sures ; and conversely its weight in grains, divided by its bulk in 

416.22 

grains, is its specific gravity sea 1.197 = 

* J 348.1975. 

After floundering through this mire of miscalculation, the 
Doctor has the modesty to say, " All the tables hitherto published, 
exhibiting the strength of muriatic acid of various specific gravi- 
ties, are very erroneous, because they were constructed upon in- 
accurate data. I conceive, therefore, that it will be worth while 
to exhibit an accurate table of the specific gravity of this acid of 
determinate strengths. My method was, to saturate a given 
weight of the acid with calcareous spar." This is to out-Herod 
Herod. " My method," as he calls it, is the old and usual one, 
and was that employed in constructing a table of muriatic acid, 
published in his own Annals of Philosophy for October ', 1817. But 
the method with nitrate of silver is incomparably more delicate 
and precise. 

What are we to think of that man's candour, who, after assert- 
ing that all the tables of muriatic acid hitherto published are very 
erroneous, gives as his own discovery, and as a standard of truth, 
a little table, of which the fundamental numbers, viz., the specific 
gravities corresponding to quantities of acid per cent, are appa- 
rently taken, without acknowledgment, from a very extensive table 
of muriatic acid published in this Journal, for January, 1822. The 
slight disguise that the Doctor has put on his numbers, will never 
make them pass for his own. 

Table in Journal of Science, Table in Dr. Thomson's 

Jan. 1822. Attempt, 1825. 


Specific Gravity. 


Acid in 100. 


Specific Gravity. 


Acid in 100. 


1.200 


40.777 


— 


1.203 


40.659 


1.1846 


37.108 


— 


1.179 


37.000 


1.1620 


32.621 


— 


1.162 


33.945 


The fundamental strength at sp. gravity 1.20 is that from which 
the numbers in the tables are deduced, and it is as nearly as may 
be the same in both. We are confident that Dr. Thomson's small 
deviations from the numbers given in our Journal for 1S22 are 
errors ; but supposing them not so, the differences are so inconsi- 
derable, as not to entitle the Doctor to say all the former tables 
were " very erroneous." 

In his fifth chapter, Dr. Thomson treats of the atomic weight of 
azote, and specific gravity of azotic gas. The usual felicity of co- 
incidence between experimental and theoretic numbers attends his 

K 2 


132 Renew of Dr. Thomson 

attempts here — a felicity, however, which he had not the courage 
to claim a very few years ago. In his long paper on the specific 
gravity of the gases, published in the 16th volume of the Annals 
{Sept. 1S20), he says, " When 100 volumes of air are mixed with 
42 or 44. volumes of hydrogen gas, and an electric spark passed 
through the mixture, the diminution of bulk always amounts 
to 63 volumes.*" His "hydrogen was then prepared from 
pure re-distilled zinc, pure water, and pure sulphuric. acid, with 
the requisite precautions." Mark his language now : — " A mix- 
ture of 100 volumes of air, and 42 volumes of this pure hydrogen 
gas, was fired by an electric spark. The diminution of bulk in 
three successive experiments was precisely 60 volumes.! " 

What confidence can be reposed in such plastic results ? 

He tries to analyze nitre, by igniting it in contact with iron 
filings contained in a copper tube. Here " chaos is come again," 
but we shall keep it, if possible, out of our pages. 

He favours us in this chapter with a brief table of liquid nitric 
acid, which seems to be taken, without acknowledgment, from a 
copious table published seven years ago in the 8th number of this 
Journal. 

Taeles of Nitric Acid. 

Dr. Thomas's Attempt, 1825. 

Specific Gravity. [AcidinlOO. 


Journal of Science 


, Jan. 181S 


Specific Gravity. 


Acid in 100. 


1.4855 


75.000 


1.4530 


66.948 


1.4189 


59.775 


1.3945 


54.993 


1.3630 


50.211 


J. 3001 


40.647 


1.2765 


37.459 


1.2402 


32.677 


1.2212 


30.286 


1.2084, 


28.692 


1.4S55 


75.000 


1.4546 


66.668 


1.4237 


60.000 


1.3928 


54.545 


1.3692 


50.000 


1.3032 


40.000 


1.2S44 


37.500 


1.2495 


32.574 


1.2173 


30.000 


1.2012 


28.571 


A table of the atomical relationships of acid and water, at dif- 
ferent densities, is given at p. 24 of our Journal of January, 
1819, from which Dr. Thomson's atomical table does not differ; 
yet he never alludes to these researches which so long preceded, 
iind in fact superseded, his own. That nitric acid of specific 
gravity 1.55, consists of 1 atom of real acid -f 1 atom of water, was 
stated in a well-known chemical publication several years before 
Br. Thomson's Attempt appeared, iiis table descends no lower than 
to 1.2012; and it obviously ranges itself as evenly by its pre- 
decessor, as decency would permit. We are certain that the 
differences, however small, will do no credit to Dr. Thomson's 
ocharacter as a chemist. 

* Page 163. f Alien f, i. 90 


on the Atomic Theory. 133 

In the 6th edition of his system, oxalate of ammonia is said 
to consist of 4.5 oxalic acid + 2.125 ammonia. But no such 
compound exists. In discussing ammonia, under azotic gas, he 
now describes the oxalate as composed of 1 atom acid + 1 atom 
ammonia, -f- 2 atoms water=8.875. This atomic weight of the 
crystallized oxalate of ammonia was first given in the Philosophi- 
cal Transactions for 1 822. 

Chapter 6th is occupied with the atomic weights of the acidi- 
fiable combustibles, carbon, boron, silicon, phosphorus, sul* 
phur, selenium, arsenic, and tellurium. 

The Doctor exposes calcareous spar to ignition in a platinum 
crucible, and gets at once, as if by a wishing-cap, the absolute 
atomic weight of carbonic acid. " The next object," says he, 
" which engaged my attention was to disengage the carbonic acid 
from 100 grains of calcareous spar, and collect it over mercury, 
in order to ascertain its volume*." The manner in which he 
tries to attain his purpose would ensure its failure, in any hands 
but those of Fortunatus. He treats 100 grains of calcareous spar 
with strong nitric acid in a retort, connected with a graduated 
glass receiver nearly filled with mercury, and inverted in a 
basin of that liquid. The beak of the retort has a stop-cock at- 
tached to it, from which a bent glass tube proceeds to the top 
of the receiver. The spar in three or four pieces is dropped into 
the tubulure of the retort ; its stopper is inserted with all conve- 
nient speed, and the stop-cock opened. We, who have made 
many similar experiments, know well that so much carbonic acid 
gas would escape in the time of introducing the spar and closing 
the retort, and so much nitric acid vapour pass over with the 
gas into the receiver, as would render the experiment nugatory 
for all atomic determinations. It, moreover, occasions too many 
chemical computations for the Doctor's arithmetic. On this oc- 
casion, he acts with a prudent reserve. He takes care not to 
state the experimental quantities, but pronounces the following 
oracular response. u All the necessary reductions being made, 
the volume of carbonic acid gas evolved from 100 grains of cal- 
careous spar, supposing the barometer to stand at 30 inches, and 
the thermometer at 60 , and the gas to be perfectly diy, amounts 
from a mean of two experiments, both made, with very great care, 
to 94.246 inchest." The Doctor has already drawn so freely on 
our credulity, that we have really none to spare for the present 
large demand. The result is plainly factitious. 

We cannot bestow a thought on his luminous details about the 
compounds of carbon and hydrogen. In a paper published in the 
Phil. Trans, for 1822, there are some facts relative to naphtha- 
line, which he has carefully concealed from the readers of his 

♦ Attempt, i. HO, f Ibid. 1 IS. 


134 Review of Dr. Thomson 

book, least by stating prior researches, he should stultify his 
own. 

Under silicon, he furnishes an amusing example of the facility 
with which mineral analyses may be twisted into any shape that 
a theorist shall fancy. Thus of nepheline, he says, " Let us sup- 
pose that in this mineral, every atom of alumina is combined 
with an atom of silica ; and every atom of soda with an atom and 
a half of silica." Again under dioptase, " Let us calculate the 
constituents of this mineral on the supposition that it is a hy- 
drated sesquisilicate of copper." Knebelite consists, according 
to him, of silicate of iron, silicate of manganese, and trisilicate 
of manganese. 

How imperfectly the Doctor is acquainted with the chemical 
habitudes of saline bodies, on which their mutual decompositions 
depend, will appear from his employing sulphate of soda as a 
reagent to detect the presence of lead. He mixes solutions of 
phosphate of soda and nitrate of lead, and tries the supernatant 
liquid, after it has become limpid, as follows : " A drop of this 
liquid was put into a watch-glass, and mixed with a drop of solu- 
tion of sulphate of soda. No precipitation or opalescence took 
place, shewing that the liquid contained no sensible quantity of 
lead O 

We affirm on the contrary, that a solution may contain a very 
sensible quantity of lead, though sulphate of soda does not 
occasion in it either opalescence or precipitation ; a fact which 
we shall state in detail presently. 

Dr. Thomson gets completely bewildered in his 7th chapter, 
on the relation between the atomic weights and specific gravities 
of gaseous bodies. Here we find him describing an arbitrary 
convention of numbers, as a law of chemical combination. The 
law is thus enunciated, " The specific gravity is equal to the 
atomic weight multiplied by half the specific gravity of oxygen 

This is a valuable piece of legislation. Dr. Thomson resolves 
that half a volume of oxygen, weighing 0.5555, when air=l, 
shall be regarded as the atomic unity, or 1 ; consequently, the 
atoms of all gaseous bodies may be represented numerically in 
reference either to that demi- volume 0.5555, or to the weight 
= 1. Hence the reduction of weights to volumes or specific gra- 
vities, is done by multiplying by 0.5555. This instead of being a 
law of chemical combination, is an annoyance created by the 
present oxygen scale, from which the hydrogen scheme is free. 
But this matter has been already discussed. Yet, after all, Dr. 
Thomson is under a mistake in ascribing to Dr. Prout the merit 
of that rule for converting the atomic weight of a body into the 

* Attempt , .200. t Ibid. 241. 


3 


on the Atomic Theory. 135 

weight of its volume in the gaseous state. It was clearly stated 
by M. Gay-Lussac, in his memoir on iodine, first published in 
1814, and translated by Dr. Thomson into his Annals for Fe- 
bruary, 1S15. We there read, " We do not know the density of 
the vapour of iodine ; but from experiments to be stated below, 
I have found that the ratio of oxygen to iodine is 1 to 15.G21. 
Now the density of a demi- volume of oxygen being 0.55179, 
0.55179 x 15.621 = 8.6195 will represent the density of iodine 
under the volume taken for unity *. 

Under alkalis and alkaline earths we can perceive no new de- 
termination of any consequence. 

The section on alumina, exhibits the atomic theory, dancing in 
masquerade among the mineral species. Thus after stating 
Rose's analysis of felspar, he proceeds as follows : " Let us 
suppose that all the bases are combined with silica, and in the 
state of trisilicates, except potash, which is a quadro-silicate ; 
and let us calculate its constitution according to that suppo- 
sition. 

(1) 2.25 : 6 :: 17.5 : 46.666 — silica united to alumina. 

[2) 6: 8:: 12 : 16=silica united to potash. 
3.5 : 6:: 1.25 : 2.143=silica united to lime. 
4.5:6::0.75: 1 ta silica united to oxide of iron t." 

In spite of all this coaxing, he is pestered with an excess of 
silica in the mineral =0.941, with which his four bases will have 
nothing to do. 

He expresses astonishment at Mr. R. Phillips's number 3.375 for 
alumina, not perceiving it to be his own number slightly travestied 
in order that alum might be content with two atoms at 3.375 = 6.75, 
instead of 3 atoms at 2.25 = 6.75. The Doctor's distress at this 
discrepancy is truly ludicrous, and will meet with no sympathy. 

But Doctor Thomson has reserved his grand atomic ballet, 
that" it might be performed on the three new earths, glucina, 
yttria, and zirconia. We shall exhibit merely an entree or two. 

" Let us now calculate the composition of eudialite, on the 
supposition that all the bases are combined with silica, in the 
state of trisilicates, except the soda, which must be in the state 
of bisilicate. 

* (1) 6 (atom of zirconia) : 6 (3 atoms silica):: 11.102 : 11.102 
= silica united to the zirconia. 

" (2) 3.5 (atom of lime) : 6 (3 atoms silica) :: 9.785 : 16.77= 
silica united to the lime. 

"(3) 4(atomofsoda) ; 4(2 atoms silica) :: 13.13 ; 13.13=silica 
united to the soda. 

"(4) 4.5 (atom of protoxide) : 6 (3 atoms silica) :: 8.8 16 : 11.75 
=: silica united to the protoxide of iron and manganese. 

* Ann. of Phil. v. 105. t Attempt, i. 302. 


136 Review of Dr. Thomson 

" Now 11.102+16.77+13.13+11.75=52.752. This is less 
than the whole silica in the mineral by 0.573. As the silica in 

combination with the zirconia constitutes — of the whole, it is 

48 

obvious that in order to have the quantity of silica united to the 

zirconia in the eudialite, we must add — of 0.573=0.12 to 

4.8 

11.102, which will raise it to 11.222. 

" This gives us, 11.222 : 11.102 ::6 : 5. 9 35 8 = atomic weight 
of zirconia V 

Does the Doctor expect any man in his senses to receive the 
atomic weight of zirconia, so deduced ? For elaborate frivolity 
we know nothing comparable to the above and its companion ar- 
ticles. The whole components of the mineral eudialite, as well 
as those of the other minerals, are undoubtedly associated by a 
reciprocal affinity ; but our author pairs them out for his atomic 
pantomime, with all the gravity of a French dancing-master. 

In the 10th chapter, on the atomic weights of iron, nickel, 
cobalt, manganese, and cerium, we have sought, but in vain, for 
any sound sample of chemical research. What is to be thought 
of such a passage as the following ? 

" From this statement it is obvious, that when 17.375 grains 
of protosulphate of iron are thus treated" (with a heat progres- 
sively raised) " 7.59375 grains of water, or 7 atoms — £th atom, 
will be driven off; 2§ grains of sulphuric acid will be converted 
into 2 grains of sulphurous acid, which will fly off, and half a 
grain of oxygen, which will convert the 4g grains of protoxide 
into 5 grains of peroxide. The remaining 2\ grains of sulphuric 
acid united with 0.28125 grains of water, the 1th atom still re- 
maining, will be driven off in the state of fuming sulphuric 
acidt." Though " this statement" is quite absurd in an analy- 
tical point of view, it may be made instructive ; for it displays 
strongly the inconvenience of the oxygen scale, compared to the 
hydrogen. The numbers, transposed to the latter scale, run thus : 
139 grains green vitriol lose first 60| in water (=63 — -2*); 20 
grains of its sulphuric acid resolve themselves into 16 grains of 
the sulphurous, which fly off, and four grains of oxygen, which 
go to the 36 grains of protoxide, converting them into 40 of 
peroxide. The remaining 20 grains of sulphuric acid, united 
with 2^ grains of water, the one -fourth atom unprovided for, will 
be disengaged in the state of fuming sulphuric acid. Will the 
Doctor maintain that the latter view is not far more intelligible 
than his, in which numbers with five decimal places of figures are 
required ? And with regard to his method of determining the 

* Attempt, i, 339. t Ibid. 347, 


on the Atomic Theory. 137 

atomic weights of the above metallic bodies, nothing can be more 
unsatisfactory. We are persuaded that his numerical results 
would be less equivocally obtained, by a collation of the experi- 
ments of other chemists with the modern atomic theory, than by 
any inference from his own researches. 

" 1 found many years ago," says he, " that when 100 parts of 
iron are oxidized by passing the steam of water over them at a 
red heat, they combine with 29.7528 parts of oxygen *." But 
from the experiments of M. Gay Lussac, it is known, that 100 
parts of iron oxidized in this way, unite with 37.8 parts of 
oxygen. So much for the Doctor's experimental precision. 

Now for his theoretical profundity. " Hence it would appear 
that this supposed oxide (of Gay Lussac), is a compound of 1 
atom iron + l\ atom oxygen gas t." 

We cannot devote much time to his second volume. Persons 
who can find amusement in haphazard experiments and gratuitous 
inferences may look into his section on uranium, particularly 
the 4th and 5th pages. M. Arfwedson made some good researches 
on the combinations of this metal with oxygen, which Dr. Thom- 
son as usual turns to his own account, by slight modifications. 
" To determine the atom of chromium I dissolved a quantity of 
chromate of potash in water, and added tartaric acid to the so- 
lution. An effervescence took place, and the solution assumed a 
fine green colour, because the chromic acid was converted into 
protoxide of chromium. Ammonia being poured into the green 
coloured liquid, the protoxide of chromium was precipitated. It 
was collected on a nitre, well washed, and dried in the open air J." 

Now we affirm that this experiment, from which he deduces the 
atomic weight of chromium, was never made, for the result is im- 
possible. Ammonia does not precipitate oxide of chromium from 
the above green solution in tartaric acid. 

When solutions of chromate of potash and tartaric acid are 
mixed, there is an immediate formation of bitartrate of potash, 
which speedily falls down ; and if the tartaric acid be in consider- 
able excess, the chromic acid will be decomposed with efferves- 
cence. But the oxide in the resulting green liquid is not preci- 
pitable by ammonia. Yet Dr. Thomson builds upon a pseudo-ex- 
periment, one of his usual atomic structures. Ex uno disce omnes. 

Our readers must, by this time, be nearly as tired, as we have 
long been ourselves, of this illusory and fantastic attempt. 

He assigns 9 for the atomic weight of crystallized oxalic acid. 
The number 7.875 first given in the Philos. Trans, for 1822, is 
undoubtedly more to be depended on, particularly since it has 
been confirmed by *' a chemical friend, of whose accuracy and in- 
formation I (Dr. Thomson) entertain a very high opinion §." 

* Attempt, i. 355, t Jbid. % Ibid. ii. 51. $ Ibid. ii. 103. 


138 Review of Dr. Thomson 

It is diverting to see the pertinacious effrontery with which he 
still refers to his experiments on oxalic acid, after the full expo- 
sure of their absurdity, in our review of his system, (6th edition,) 
and in our remarks on his answer to that review *. 

He now sets to work, in his usual way, on the crystalline hy- 
drate, to ascertain, whether or not, oxalic acid contains hydrogen. 
This point has, however, been determined so fully by the most 
delicate and decisive experiments, as utterly to supersede Dr. 
Thomson's tardy intervention. 

Dr. Thomson's experiments to ascertain the atomic weight of 
tartaric acid betray a rudeness in practical chemistry, unaccount- 
able in so old a hand. He describes tartrate of potash, as con- 
taining two atoms of water, separable by heat. The anhydrous 
salt has, according to him, an atomic weight of 14.25, to which 
8.25 sea 2 atoms of water being added, the sum 16.5 will be the 
number of the crystallized salt. 14.25 of the anhydrous salt, 
corresponding to 16.5 of the crystals, were found by him exactly 
equivalent to 20.75 of nitrate of lead. " The mother water (of 
the mixed solutions of these two salts) was tested with nitrate of 
lead, and tartrate of potash, without being in the least affected 
by either. Hence it contained no sensible quantity either of tar- 
taric acid or of lead. The whole of these two bodies was contained 
in the precipitate which had fallen." 

His number for tartrate of potash is unquestionably wrong ; 
and, indeed, though it were right, his conclusion would be erro- 
neous. For the mother water (as he elegantly terms the limpid 
supernatant liquid) contains, under his proportions, both tartaric 
acid and oxide of lead. Let it be tested with sulphate of soda, 
and it will become cioudy ; with sulphuretted hydrogen, and it 
will become very black ; or with nitrate of lead, and tartrate of 
lead will fall. Thus the principle of Richter, of whose applica- 
tion our Doctor is so vain, becomes, under his management, quite 
deceptious. 

His determination of the atomic weight of acetic acid is liable 
to the same objections. He mixes solutions of 8.875 gr. of oxa- 
late of ammonia (its true atomic weight appropriated as usual to 
himself, from a prior memoir in the Phil. Trans, for 1822) and of 
23.625 grains of acetate of lead ; and tests the supernatant li- 
quid " by sulphate of soda and muriate of lime." Now we have 
the pleasure of informing the Regius Professor of Chemistry, 
that as a test of lead, sulphate of soda is good for very little on 
the present occasion ; and indeed no accurate chemist would trust 
to it. Acetate of lead and sulphate of soda can co-exist to a very 
considerable extent in a clear solution ; as the youngest tyro may 
prove, by adding to one portion of the supernatant liquor, muriate 

* Quarterly Journal, xi. 155, and iii. 349. 


en the Atomic Theory. 139 

of barytes, and to another portion of the same, sulphuretted hy- 
drogen or prussiate of potash. In the first case, a copious pre- 
cipitate of sulphate of barytes will prove the presence of sul- 
phate of soda ; in the second, sulphuret, or ferro-prussiate of 
lead, will fall. In fact, let solutions of sulphate of soda and ace- 
tate of lead be mixed in the proportions indicated by Dr. Thom- 
son's atomic weights of these salts, or in the most exact equiva- 
lent proportions ; a portion of sulphate of lead will fall, and a 
corresponding portion of acetate of soda will be formed. To 
the supernatant liquid, (of any atomic proportion,) add carbonate 
of soda, and carbonate of lead will be separated in abundance. 
When the alkali ceases to act, let a current of sulphuretted hy- 
drogen be passed through the supernatant liquid, and sulphuret 
of lead will appear. Thus also ferro-prussiate of potash will 
detect lead in a solution, when the proportion is too minute for 
the carbonate of soda test. 

Dr. Thomson, from his unaccountable ignorance of these gra- 
dations of affinity, has given, as experimental results, quantities 
which it was impossible to obtain by the method of precipita- 
tions. And, hence, had they not been rendered conformable to 
the researches of Berzelius and other accurate chemists, as well 
as to the theory of equivalents, the odds would have been ten to 
one against Dr. Thomson's numbers in almost any case. 

The above remarks apply strongly to his sections on citric, 
tartaric and acetic acids. And we are somewhat surprised that 
he should expect any attention to his experiments on the ultimate 
analysis of vegetables, in which upwards of nine grains of the 
above crystalline acids are treated with only 200 grains of per- 
oxide of copper. No certainty of their thorough decomposition, 
by the oxygen of the ignited oxide, can be ensured ; and the re- 
sult must be destitute of all authority. 

We have now adduced ample, even superfluous, evidence, of 
the strongest negligence or incapacity in the conduct of his re- 
searches on the atomic theory. And moreover, the perplexity 
into which he runs, in considering the partial and erroneous ca- 
nons of Berzelius, is a decisive proof that his general views are 
neither clear nor comprehensive. In our Journal for January 
1822, page 307, we endeavoured to shew the fallacy of these 
pretended general laws of Berzelius. This development of ours 
seems to have fallen under the Doctor's talons in an unhappy hour ; 
for he tortures and disguises it most unmercifully. We request 
our readers to compare the passage referred to in our Journal, 
with Dr. Thomson's " few words respecting Berzelius's law," at 
p. 469, et seq. of his lid. volume. 

The style of writing adopted by the doctor, in this new work, 
ill accords with the lofty panegyric pronounced by himself, on 
his literary attainments. / am remarkably concise, tluough I hope 


140 Review of Dr. Thomson on the Atomic Theory. 

ahuays clear, and generally energetic*." We humbly apprehend, 
that more obscure, flat, and tautological phraseology, than that of 
which the present " Attempt" is made up, is not to be found within 
the precincts of any English book -factory. Its periodic move- 
ments are heavy and reluctant like those of a worn-out atmo- 
spheric engine. 

In a prefatory address to the students of medicine and che- 
mistry in the University of Glasgow, he advertises them, that 
his " future courses of lectures will be more entertaining and va- 
ried." He assures us that his first reason for publishing this 
book, " is the great advantage which medical practitioners will 
derive from a knowledge of the atomic weights of bodies, and of 
the weights of the integrant particles of the salts, &c, which they 
have occasion to employ in their prescriptions. This knowledge 
will be easily acquired by a perusal of the following pages ; and it 
will enable those who possess it, to avoid some very awkward 
blunders into which I have observed too many practitioners, even 
of considerable celebrity, frequently to fall, to the no little incon- 
venience of their patients t." 

Does Dr. Thomson know a physician, celebrated for his medi- 
cal attainments, in a printed circular, addressed by himself, to the 
directors of a royal infirmary, who, to the no little inconvenience 
of his patients, prescribed the fashionable medicine prussic acid, 
under the form of prussiate of mercury ? Fortunately, this vi- 
rulent poison was rejected by the stomach before it had time to 
shew the power of an atomic theorist on medical prescription. 
We may next hear of corrosive sublimate being substituted for 
muriatic acid ; since they have the same relation to each other as 
the above two bodies. 

Of the merit of his work, the Doctor speaks so authorita- 
tively as to set criticism at defiance. Having affirmed that the 
present publication will be of no little service to all medical 
men, and medical students, he says ; " The tables contained in 
this work ought to occupy a place in every laboratory, and to lie 
upon the shop of every druggist, that he may have it in his power 
to have recourse to them to regulate all his processes J." 

The fashion of paper roofs having gone out, we think it doubt- 
ful whether his pages will have the fortune to lie upon the shop of 
every or even of any druggist ; but there is another shop where 
a pulverulent drug is retailed, on whose counter his pages may 
possibly appear. 

Conceit of knowledge prevents its acquisition. Dr. Thomson, 
having persuaded himself that all his experiments, however ill- 
devised or ill-executed, are of infinite value and perfect precis 

* Annals of Philosophy for April, 1822, p. 245. 
t Atternpt/i. Preface viii. % Ibid. Preface xiv. 


Captain Sabine on the Figure of the Earth. 141 

sion, modestly tells us, that Berzelius and Dulong are in error by 
-j^th part, while his own results are quite correct ; though in 
reality they are incomparably more inaccurate, when their errors 
are not veiled by counterbalancing errors in arithmetic. 

There are a few passages of his work composed in a better 
spirit, and rather freer from the arrogance that blinds him. On 
these we would willingly have bestowed commendation, had the 
author not forestalled for himself every laudatory form of ex- 
pression. 


II. An Account of Experiments to determine the Figure of the 
Earth by means of the Pendulum vibrating Seconds in different 
Latitudes ; and on various other Subjects of Philosophical Inquiry. 
By Captain Edward Sabine^F.R.S. &c. Printed at the Expense 
of the Board of Longitude. Murray. 

[The following- Review of the first part of Captain Sabine's Work, namely 
of his Experiments on the Figure of the Earth, has been transmitted 
to us from a Correspondent in the United States. We are glad to 
perceive that the Works of British Science are so quickly and so 
justly appreciated on the other side of the Atlantic] 

From the time of the first cultivation of science, the size and 
figure of the earth have been objects of inquiiy. To an ignorant 
and superficial observer, it presents the appearance of an ex- 
tended plane ; to the earliest cultivators of Astronomy, it shewed 
an evident curvature in the direction of the meridian ; and it was 
not long before a curvature in a transverse direction was also 
detected by means of a difference in the apparent time of the oc- 
currence of Lunar eclipses in different places : hence the earth 
was justly inferred to be of a figure nearly spherical. Other ob- 
servations have confirmed the near approach of this inference to 
the truth : the shape of the section of the shadow in lunar eclipses 
is always circular ; the appearance of great expanses of water is 
manifestly spherical ; ships in departing from the shore are hid- 
den by the curvature of the earth, long before distance alone 
could render them invisible ; and Humboldt, upon the Peak of 
Teneriffe, observed an angle of 92° between his visible horizon 
and the zenith. All these, and innumerable other facts, lead to 
the confirmation of the received opinion, that the earth is, if not 
an exact sphere, of a shape that differs but little from that re- 
gular geometric solid. 

Were the earth at rest in space, and had it originally existed 
in a fluid state, its several particles would, by their mutual at- 
traction, have arranged themselves in a spherical form ; had the 
matter of which it is composed been incompressible and homo- 
geneous, this sphere would have been of equal density through- 


142 Captain Sabine on the 

out ; but if its substance had admitted of compression, the outer 
portion would have been the most rare, and the mass would have 
increased gradually in density to the centre. 

But the form of the earth is affected by another circumstance. 
When a body is made to revolve around a fixed axis, its several 
particles describe circles, whose planes are perpendicular to, and 
centres are in the axis. In this way all the particles, except 
those situated in the axis itself, become affected by a centrifugal 
force, that, did no other power oppose its action, would cause 
them to fly off, in tangents to the curves in which they revolve : 
this force is in each particle proportioned to the radius of the 
circle it describes. In solid bodies the attraction of aggregation 
is, generally speaking, sufficient to prevent any disintegration, as 
a consequence of the action of the centrifugal force ; and in the 
larger masses of matter, whether solid or fluid, the attraction of 
gravitation produces the same effect. Our earth is a body that 
is in a state of rapid rotatory motion, performing a complete re- 
volution around its axis in the space of a sidereal day. Each 
point upon its surface is therefore acted upon by a centrifugal 
force. This is greatest at the Equator, and becomes zero at the 
Poles ; and although the attraction of gravitation is far more 
than sufficient to render this centrifugal force of no effect, in 
throwing off any portion of the matter of which the earth, or its 
surrounding atmosphere, is composed, it is yet rendered manifest 
by a diminution in the intensity of the force of gravity. This 
diminution of the intensity of gravitation will affect the rate at 
which heavy bodies fall to the surface of the earth, and the time 
of the oscillations of pendulums. It was first observed by Richer, 
a French astronomer, who visited Cayenne in 1672, for the pur- 
pose of making astronomical observations : he was furnished with 
a clock that marked mean solar time in the latitude of Paris ; and to 
his surprise he found that at Cayenne, in Lat. 5° N. its rate had 
become 2' 28" per day too slow. As this was a far greater 
change than could be accounted for by any alteration in the 
length of the pendulum, caused by difference of temperature, no 
explanation remained, except that furnished by the opposition of 
the centrifugal force to the attractive power of the earth. The 
centrifugal force, as has already been stated, is proportionate, at 
any point of the earth's surface, to the radius of the circle de- 
scribed by that point in its diurnal revolution, or to the cosine of 
the latitude : but this is not the measure of the diminution it 
causes in the intensity of gravitation ; for the latter acts in the 
direction of a radius of the terrestrial sphere, while the former is 
parallel to an equatorial diameter : on account of this obliquity of 
action, the diminution in the force of gravity, arising from the 
diurnal rotation of the earth, is everywhere proportioned, not to 
the cosine of the latitude simply, but to its square. 


Figure of the Earth. 143 

The investigations of Newton and Huygens into the laws that 
regulate the action of central forces, furnish us with means, by 
which the relation between the whole gravitating force of the 
earth, and its diminution at the Equator, under the action of a 
centrifugal force, may be determined : supposing the earth to be 
a sphere, this ratio is that of 2S9 to 1 ; but in consequence of the 
flattening of the earth at the poles and its increased diameter at 
the Equator, of which we are about to speak, this relation is 
c -hanged, and the centrifugal force bears a somewhat higher pro- 
portion to that of gravitation. A great part of the surface of 
the globe is covered with water, and many of the hypotheses of 
geologists suppose that the earth was originally in a liquid state. 
The figure of the earth, and the curvature of its surface, is that 
which the surface of the great mass of water spontaneously as- 
sumes ; and hence grew the belief that the shape of our globe 
cannot be that of a perfect sphere ; for were the solid nucleus of 
the earth perfectly spherical, the waters of the ocean must have 
accumulated themselves, by virtue of the centrifugal force, in a 
zone on each side of the Equator. 

In order that a mass of fluid acted upon by its own gravi- 
tation, and the centrifugal force arising from its rotation 
around an axis, should be at rest, and have no tendency to 
move towards either its Poles, or its Equator, it is necessary, 
that the pressure of all the columns of fluids, extending from 
the centre to the surface, should be equal to each other. These 
several columns, if enclosed in tubes, communicating with each 
other at the centre, would therefore be in equilibrio; but a 
column beneath the Equator, being formed of matter whose 
gravity is diminished by the centrifugal force, must be longer 
than one terminating at the Pole, and the lengths of the inter- 
mediate columns must vary according to their latitude. The 
figure that would result from such a state of equilibrium, was 
investigated by both Newton and Huygens, but upon two different 
hypotheses. Newton conceived the force of gravity to arise from 
the mutual attraction of all the particles that compose the earth, 
acting upon each other with forces inversely proportioned to the 
squares of their respective distances ; he thence inferred, that 
this force was not a constant one, and that if the figure of the 
earth was due to the attraction of gravitation, the intensity of 
this force at different points was affected by the earth's figure. 
The earth being once flattened by the centrifugal force, this very 
change of figure would render the force of gravity at the Equator 
the least intense : applying this theory to a homogeneous spheri- 
cal mass, and assuming, most happily, that an ellipsoid of revo- 
lution would fulfil the conditions of equilibrium, he inferred that 
the proportion between the polar and equatorial diameters was as 
229 to 230, and the compression -j-j^th part of the greater axis. 


144 Captain Sabine on the 

Huygens, on the other hand, denied that the particles were mu- 
tually attractive of each other, and assumed that each particle 
tended towards the common centre, with a force inversely as the 
square of its distance from that point ; by means of this hypo- 
thesis, he concluded that the curve by whose revolution the ter- 
restrial spheroid was generated, was not a conic section, but a 
curve of the fourth order, although, when the centrifugal force 
bore but a small proportion to gravity, it would not differ sensibly 
from an ellipsis. He found the proportion between the greatest 
and least diameters of this curve to be as 577 to 578, and a con- 
sequent ellipticity of - s \-^. Different as are these two hypotheses 
and their results, there is still one remarkable accordance between 
them, for by both the sum of the fractions that express the ellipti- 
city, and the excess of gravity at the pole over that at the Equa- 
tor, are identical. 

The hypothesis of Huygens is now exploded, inasmuch as the 
mutual attraction of all gravitating bodies is admitted ; but his 
investigation is not of the less value, for it gives the flattening 
that would take place, under the received law of attraction, pro- 
vided the earth were composed of concentric shells, infinitely rare 
at the surface, and infinitely dense at the centre : and as New- 
ton's investigation gives the compression in the case of uniform 
density, we have thus the extreme limits between which every 
possible difference in the ellipticity of the earth that can arise 
from a difference in its internal constitution, must be comprised. 

The inferences of Newton were confirmed by Clairaut, who fur- 
nished strict demonstrations of two propositions assumed by that 
great philosopher; these are — 1. That the elliptic figure satisfies 
the conditions of equilibrium ; and, 2. That the centrifugal force 
varies with the square of the cosine of the latitude. He also de- 
monstrated a theorem that has since been of much use in deter- 
mining the shape of the earth, from observations on the intensity 
of gravity. This important theorem is as follows, viz., The sum 
of the two fractions, one of which represents the ellipticity of the 
earth, and the other the ratio of the force of gravity at the Poles to 
that at the Equator, is equal to f of the fraction expressing the ratio 
of the centrifugal force at the Equator to the force of gravity. 

We are only acquainted with the mere crust of the globe we 
inhabit ; but reasoning from the nature of the substances of which 
it is composed, we might infer an increase in its density, between 
the surface and the centre. The same inference may be drawn 
from the experiments of Cavendish with the Balance of Torsion, 
and the observations of Maskelyne on the attraction of the moun- 
tain Schehallion: from these different methods a mean density 
may be inferred of not less than four and a half times that of 
water, while the outer shell has a specific gravity considerably 
below 3. Laplace, too, assuming the density of the surface to be 


Figure of the Earth, 145 

three times that of water, has inferred a mean density of 4.746. 
It will therefore be evident that the ellipticity ought to be less 
than tj-^ ; but the mere application of the calculus does not fur- 
nish the measure of its true amount, for we are ignorant of the 
nature of the substances under investigation, and the circum- 
stances under which they were first united in one mass. Had the 
earth been originally a fluid, with a compressibility equal to that 
found to exist in water by the experiments of Canton, the ellip- 
ticity would have been 3-^ ; but this hypothesis is probably wide 
of the truth, and the inferred ellipticity consequently incorrect. 

In order to ascertain the real figure of the earth, it is absolutely 
necessary to have recourse to experiment and observation. The me- 
thod that would at first appear most obvious, is that of actually 
measuring a portion of one of its meridians : should its degrees be 
found all equal, a truly spherical figure might be inferred ; should 
they decrease from the Equator to the Pole, an elongation would be 
proved ; but should the degrees nearest to the Pole be found the 
•longest, no doubt need be entertained that the earth is flattened 
in the direction of its axis of revolution. With these views a 
portion of a meridian, extending from Dunkirk to the southern 
frontier of France, was measured by Picard and Cassini. The 
apparent result of this operation led to conclusions totally differ- 
ent from those deduced from the theory of gravitation, and the 
laws of central forces. The southernmost degrees of this arc ap- 
peared to be the longest ; and thus ground was afforded for the 
belief that the earth was an oblong instead of an oblate spheroid*. 

The measure of Picard and Cassini being at variance with the 
received hypothesis, but the instruments and methods of the age 
being insufficient to discover the error, it was proposed, by way 
of ascertaining the truth in the most unexceptionable manner, to 
measure a degree under the Equator, and another as near to the 
Pole as was practicable. With this view, Maupertuis was sent to 
Lapland, and Condamine to Peru. Their measures confirmed the 
general theory of Newton, in manifesting the oblateness of the 
earth. The degree of Maupertuis, compared with those measured 
in France, gave for the fraction expressing the degree of oblate- 
ness, y\^ ; but by a recent measure of the same degree by Soan- 
berg, an error of more than 200 toises, in excess, has been 
detected, and the determination of this astronomer, compared with 
degrees measured in France, reduces the flattening to j^ f . The 
French arc has subsequently been extended into Spain, and as 
far south as the island of Formentera. In England an arc of 

* The same arc has since been more correctly measured by Mechain and 
Delambre, towards the end of the last century, by which a different result was 
obtained, giving the fraction 2 *j for the flattening at the Poles. 

Vol. XX. L 


146 Captain Sabine on the 

three degrees, extending from Dunnose, in the Isle of Wight, to 
Clifton, was measured by General Mudge, and it has since been 
extended as far as Unst, one of the Shetland islands. Various 
other arcs have been measured at different times, as, at the Cape 
of Good Hope, by La Caille ; in Pennsylvania, by Mason and 
Dixon ; in Italy, by Boscovich ; in Hungary, by Liesganig ; and 
in India, by Lambton. If many of the contiguous partial arcs 
show an elongation, still all, when compared with others at a con- 
siderable distance, to the north or south, show a flattening towards 
the Poles : but, although this may be considered as fully esta- 
blished, there yet remains very considerable doubt as to the value 
of the fraction that expresses the relation between the Polar and 
Equatorial diameters of the generating ellipsis ; the results, ob- 
tained by comparing the different measurements with each other, 
varying so greatly as scarcely to have narrowed the question 
within the limits in which it had been reduced by the hypotheses 
of Newton and Huygens, and the demonstrations of Clairault. 

This variation, particularly where recent measures are con- 
cerned, is not attributable to a deficiency either in the observers, 
the instruments, or the methods of observation and calculation. 
It appears to be occasioned principally, if not entirely, by the de- 
flection which the plumb-line undergoes, from the unequal density 
of the materials near the surface of the earth, and which affects 
the celestial determination of the latitude at the extremities of 
the measured arc : no means are as yet known by which the 
errors thus occasioned may be avoided, or their amount ascer- 
tained and allowed for. It is to their influence that we must 
ascribe the fact, that by combining together the French and 
British surveys, whereby an arc of nearly a fourth of the quad- 
rant of the meridian is obtained, the ellipticity deduced is much 
greater than would appear, from a comparison of the separate 
degrees of this very arc with those measured near the Equator. 
If a precise determination of the figure of the earth can ever be 
hoped for by the measurement of portions of the meridian, it can 
only be by the comparison of arcs of very considerable extent, 
certainly of not less than five degrees, accomplished at parts of 
the meridian extremely distant from each other. 

Other methods, however, exist, that are liable to less uncer- 
tainty. The accumulation of matter in the Equatorial regions 
modifies the action of the earth upon the moon, insomuch that 
the motion of the latter is affected by two irregularities — one in 
latitude, and the other in longitude. The maximum effect of 
these equations may be determined by observation ; and hence 
the extent of the cause may be investigated. The calculation 
has actually been made by Bouvard, Burg, and Burkhardt, at the 
instance of La Place, and gives an ellipticity of -^fa. This me- 


Figure of the Earth. 147 

thod lias a great advantage over actual measurement, for it is 
independent of irregularities on the surface of the earth, or or 
inequalities in its internal constitution. 

Observations upon the length of the pendulum, beating seconds 
in different latitudes, also furnish a method by which the compres- 
sion may be determined. Tfye length of the seconds pendulum 
may be demonstrated to be exactly proportioned to the force of 
gravity at the place of observation. The comparison of such 
observations at different latitudes will afford the data for calcu- 
lating the lengths of the pendulum at the Pole, and beneath the 
Equator : these being respectively proportioned to the gravitating 
forces at these places, give the numerator and denominator of a 
fraction, that subtracted from £ of ^^, furnishes an expression 
for the oblateness of the generating ellipse in conformity with 
the theorem of Clairaut. This mode of determining the figure of 
the earth is better, for several reasons, than that of ascertaining 
the same fact, from the measure of degrees, whether distant or 
contiguous. 

It has been shewn by the investigations of Laplace, that the 
term of the formula in which error may arise from the causes of 
anomaly, has a coefficient, that is five times as great when the 
ellipticity is inferred from degrees of the meridian, as it is when 
it is determined from the lengths of the pendulum in different 
latitudes. The mode of ascertaining the length of the pendulum 
vibrating seconds has been of late years so much improved, as to 
have become a very simple experiment, that may be well per- 
formed by a single competent observer; while the measure of a 
degree of the meridian is a laborious, tedious, and expensive 
process. 

The work, whose title appears at the head of the present 
article, is for the most part occupied with an account of experi- 
ments, made to determine the length of the pendulum vibrating 
seconds in different latitudes, and in both hemispheres. They 
were performed during two voyages made in public vessels, and 
in the employ of government : in the first, the author visited and 
performed experiments at Sierra Leone, St. Thomas', the Island 
of Ascension, Bahia, Maranham, Trinidad, Jamaica, and New 
York; during the second, he landed, and experimented, at Ham- 
merfest, Fairhaven in Spitzbergen, on the coast of Greenland, 
and at Drontheim. 

The method principally relied upon by our author, and employed 
by him at all his stations, is the same which was previously used 
by Captain Kater at the several stations of the British Trigo- 
nometrical Survey, as detailed by him in the Philosophical Trans- 
actions for 1819. The fundamental experiment of this method 
consists in suspending a pendulum alternately, from two knife 

L 2 


148 Captain Sabine On the 

edges, one in the usual position of the centre of suspension, 
the other near the lens of the pendulum : the vibrations of the 
pendulum, when suspended from these two distant points, are 
rendered isochronous, by a change in the position of a small 
weight that slides along the pendulum-rod ; the point near the 
lens is thus rendered the centre of oscillation, in consequence 
of a property of the pendulum discovered by Huygens, who de- 
monstrated that the centres of oscillation and suspension were 
convertible points. The distance between the knife edges may 
"be measured with great accuracy by means of microscopes 
attached to accurate scales, giving thus the true length of the 
experimental pendulum : the number of oscillations it performs 
in any given time may be ascertained by comparison with the 
pendulum of a well-regulated clock ; and hence the length of the 
pendulum vibrating seconds at the place of experiment may be 
.determined, by applying the well-known proposition that the 
lengths of pendulums are inversely as the squares of the num- 
bers of their respective vibrations in equal times. After the 
length of the seconds pendulum has been thus determined in any 
-one place, by experiments sufficiently multiplied to ensure against 
any probable error, another pendulum of similar shape to the 
first, with the exception of its having no moveable weight, and 
but one knife edge, which is situated at the usual centre of sus- 
pension, is employed. This pendulum may be hung up in front 
of the clock, with which the original experiment was made, or of 
some other whose rate is known, and which is placed in the 
same apartment : its rate of oscillation may be thus known, and 
its length calculated, upon the same principle as that which we 
have stated as the mode in which the length of the seconds 
pendulum was originally determined. The length of this last- 
mentioned experimental pendulum being thus ascertained, and 
with an accuracy equal to that of the fundamental experiment, it 
may be carried from station to station ; the number of its vibra- 
tions, in a given time, as shewn at each station by comparison 
with an astronomical clock, will furnish data whence the length 
of the pendulum, vibrating seconds at that place, may be calcu- 
lated. This method is undoubtedly the best that has hitherto 
heen proposed, and we are not prepared to say that it is sus- 
ceptible of any material improvement in the theoretic part ; the 
manner o£ construction or even of using the instrument may 
perhaps undergo change, {the latter has undergone a very im- 
portant change since its first employment by Captain Kater, in 
the improved method suggested by Captain Sabine, and adopted 
fry him, of observing the coincidences,) but we cannot fairly 
anticipate that any principle more beautiful, or more readily 
reduced to practice, is likely to be discovered. 


Figure of the Earth. 149 

The method employed by the French philosophers, in operations- 
of the same nature, at several points of the arc of the meridian 
passing through France, and subsequently by Biot at Unst and 
Leith, is entirely different ; and is the invention of Borda. He 
suspended in front of an astronomical clock a sphere of platinum, 
by means of a slender iron wire, whose length was about four 
times that of the clock pendulum ; the wire was made of iron, in 
consequence of the great tenacity of that metal, which would 
pennit it to be drawn of great fineness without rendering the 
wire liable to break by the weight of the ball : the coincidences 
of this wire, with a cross or mark upon the lens of the clock 
pendulum, were observed by means of a small telescope placed in 
front. After the pendulum was brought to rest, its extreme 
length from the point of suspension to the lower surface of the 
spherical body was measured, while it remained suspended ; the 
distance between the centres of oscillation and suspension, or the 
effective length, was found by calculation, founded on well 
known formulae, on the supposition that the wire was devoid of 
weight ; and a correction finally applied for the weight of the 
wire. In this method, each observation is entirely independent 
of any other, and rests upon its own merits ; whilst in the 
method, employed by Captains Kater and Sabine, in which the 
relation only is determined, which the length of the seconds 
pendulum, at the stations to which the pendulum of comparison 
is carried, bears to the length at the station of the fundamental 
experiment, — the correctness of the absolute length at those sta- 
tions will depend upon the accuracy of the original determination. 
But this need not be a disadvantage, even in determining the 
absolute length at the several stations, because the fundamental 
experiment may be frequently repeated, until perfect accuracy 
may be considered as attained ; and certainly is none, in the 
application of the results to the deduction of the figure of the 
earth : because in such case it is the relation only, and not the 
absolute length, which is the object of precise inquiry. 

The method of Borda has recently been altered by Biot, who 
uses a pendulum of less length ; the apparatus may thus be more 
securely and conveniently carried from place to place, enclosed 
in a glass-case. In spite of this improvement, the method of 
Kater is well entitled to the preference ; the first experiment 
requires no greater care or precautions, and will occupy less time 
than every separate determination by the method of Borda ; and 
in every subsequent trial, the British method is very much 
more speedy, is capable of more accurate and comparable 
results, and is less dependent either upon external circumstances, 
or upon the skill of the observer. 

Besides the method which wc have described, our author made 


150 Captain Sabine on the 

use of two others, as checks upon his experiments ; the first was 
that of an invariable pendulum attached to a clock ; the second 
arose from the variations in the rate of the astronomical clock in 
different latitudes : we refer to them only as having fully con- 
firmed the results of his other experiments, for their principle is 
too well understood to need any illustration. 

Captain Sabine, after having recounted his several observa- 
tions of coincidences of the pendulums ; of the rate of the clock 
-with the invariable pendulums ; of transits and altitudes of the 
Sun and stars for the rate of the astronomical clock and chrono- 
meters ; of meridian altitudes of the heavenly bodies for the lati- 
tudes of the places of observation, — all with a fulness of detail, 
which will enable those who may desire to do so, to trace every 
step of the process from the original observations to the ultimate 
conclusions, — proceeds to combine his determinations, for the 
purpose of calculating the compression of the earth. The mode 
he employs, using the thirteen stations visited in his voyages, is 
that given by Laplace, in the third book of the Mechanique Celeste, 
founded upon the principle of the least squares. 

His calculation gives the fraction — 1— - for the compression : a 
very remarkable result, in consequence of its being the same that 
expresses the ratio of the centrifugal to the gravitating force. Not 
content with his own measures, he has next combined them with 
those of Kater, at the stations of the British, and of Biot, Arago, 
§-c, at those of the French survey ; and in every combination he 
is led to the same result. With such a confirmation, we are 
Warranted in saying, that we conceive this value for the compres- 
sion of the terrestrial spheroid, is more entitled to confidence, 
than any other that has yet been given ; and when we consider 
its remarkable agreement with the ratio of the central forces, we 
cannot help believing that there may be some connexion between 
the external figure of the earth, and its internal constitution, that 
still remains to be investigated, and which we consider highly 
deserving the attention of the few mathematicians in the World 
who are competent to the investigation. 

This determination of an ellipticity of — ± — differs much from 
any other, whether derived from former experiments with the 
pendulum, from the measure of contiguous, or of distant arcs of 
the meridian. It is, however, entitled to the highest confidence, 
inasmuch, as it is the first that has been drawn from observations 
of the pendulum, unconnected with any other operation. It is 
very remarkable, that, whilst the pendulum has a right to be con< 
sidered as a mode of determining the relation between the polar 
and equatorial axis, perhaps more certain than any other, it has 
never before the present day, formed the principal object of ob- 
servation, but has always been confided to the same persons, who 


Figure of the Earth. 151 

were employed either in performing geodetic operations, or in 
calculating their results. We would not charge these distin- 
guished philosophers with unfairness ; they are far above any 
such suspicion ; but would merely remark the singular coincidence 
that has from time to time been found, between the deductions 
obtained by means of the pendulum, and by the actual measure of 
arcs, when used to confirm each other. The French commission, 
who reported the Systime Metrique, inferred an ellipticity of -g^g-. 
by comparing the degrees measured in France with that mea- 
sured in Peru; and this oblateness is employed by them as the 
foundation of that system, so beautiful in theory. Laplace, who 
was one of that commission, calculated the compression of the 
earth, from 15 lengths of the pendulum, measured at different 
places, and inferred that it was-g-^. This, if accurate, might have 
fairly been received as a strong confirmation ; but on examina- 
tion of his calculation, as given in the third book of the Mecha- 
nique Celeste, an error in taking out a logarithm will be detected ; 
and correcting this mistake, the deduced ellipticity, by his method 
of calculation, would be increased to -g-j ? . Since that period, 
and when the compression deduced from the measure of more dis- 
tant arcs, became T ^ ; and that which agrees with the inequali- 
ties in the lunar motion, arising from the shape of the earth, is 
supposed to be about ^^ ; the same illustrious author, by admit- 
ting the new observations of Biot and Arago, infers from the 
general combination of pendulum experiments, an ellipticity ofg-f^. 
No better proof can be afforded than this, of the facility with 
which the few observations that had been made, before the pen- 
dulum was taken up by Great Britain, as a distinct and independ- 
ent method, could be made to agree with any hypothetical oblate- 
ness of the terrestrial spheroid, when examined merely for the pur- 
pose of confirming, or disproving the calculations, whose data are 
derived from other sources. It is now time that the pendulum 
should assume the rank of an independent measure of the rela- 
tion between the two diameters of the earth; and the credit is 
due to Captain Sabine, of having been the first experimental phi- 
losopher, who has distinctly asserted its equal claim, as well as 
proved by his experiments its right to be so considered. His ex- 
periments have, in fact, done more than place it on an equality, 
as present authority, with the measurement of terrestrial degrees : 
in his hands, it has become the only method of deducing the fi- 
gure of the earth, which, as yet, has given a precise and determi- 
nate result. 

We fully concur in Captain Sabine's opinion, that the satisfac- 
tory and conclusive nature of the result, which the pendulum has 
afforded, when the experiments with it have thus been duly and 
sufficiently extended, presents a strong ground of encouragement 


152 Captain Sabine on the 

to attempt an equally conclusive result, by the comparison of ter- 
restrial measurements undertaken on the same decisive scale, of 
which, his experiments with the pendulum afford the example. 
He has suggested a proceeding towards the attainment of such a 
result which we cannot do better than lay before our readers, 
adding our persuasion that it is well entitled to the serious con- 
sideration of every man of science, who, either in his public 
Or private capacity, may have it in his power to promote its 
execution. 

" The success which has thus attended the attempt to carry into 
effect, under the conditions most favourable for the experiment, 
the method of investigating the figure of the earth by means of 
the pendulum, and the consistent and precise result, far exceed- 
ing previous expectation, which, under such circumstances, it has 
been found to aiford, encourage the belief that an equally satis- 
factory conclusion, and one highly interesting in the comparison, 
might be obtained by the measurement of terrestrial degrees, 
performed also under the requisite conditions to give its due effi- 
ciency to the method of experiment. Experience has fully shewn, 
that no result of decisive character is to be expected from the re- 
petition or comparison of measurements in the middle latitudes ; 
and that it is only from operations carried on in portions of the 
meridian widely separated from each other, that such an event 
can be regarded as of probable accomplishment. The project of 
the original experimentors, — of those eminent men, who nearly a 
century ago, devised and executed corresponding measurements 
at the equator and at the arctic circle, — was of far more vigorous 
conception, than the steps of their successors have ventured to 
follow, even to the present period ; and it is due to their memory 
to recognise that the failure on that occasion was not from insuf- 
ficient extension of view, or from deficiency in the spirit of en- 
terprise ; but from the attempt having been made in the infancy 
of practical science, when the instruments were inferior, and the 
modes of their most advantageous employment less understood, 
than they have since been rendered. 

" The discordancies, which appear in the comparison of the mea- 
surements hitherto accomplished, are not so great as those which 
had resulted from the comparison of pendulum experiments, pre- 
viously to the present attempt to give the latter method its full 
and efficient trial : it has been also seen that in proportion as the 
arcs have been enlarged, so as to include the continuous measure- 
ment of more extended portions of the meridian, and as the pro- 
cesses of operation have been conducted with improved means, 
and increased attention to accuracy, the anomalies have progres- 
sively diminished ; the prospect therefore, that they may be made 


Figure of the Earth. 153 

wholly to disappear, by combining the interposition of the greatest 
interval between the measurements that the meridian of an hemi- 
sphere will admit, would seem sufficiently probable to justify and 
induce the undertaking. 

" Through the munificent liberality and splendid patronage of 
the East India Company, India already presents a determination 
of the arc contained between the 10th and 20th parallels : and as 
a consequence of the political changes which have recently taken 
place in South America, there is reason to hope, that the impe- 
diments to a measurement between the equator and the 10th de- 
gree, in the quarter of the globe best suited for the operation, 
will speedily be removed. 

" In regarding the polar extremities of the meridian, the atten- 
tion is naturally directed in the first instance to Spitzbergen, as 
the land of highest convenient access in either hemisphere ; its 
qualification, in that respect, is indeed far beyond comparison 
with other lands, and is a point of very principal importance ; its 
high latitude and conveniency of access do not, however, form its 
only suitability ; for, on due consideration, it will be found to pos- 
sess many very peculiar advantages for the operations of a trian- 
gulation. 

" The general geological character of Spitzbergen is a group of 
islands of primitive rock, the ordinary hills of which are from 
1000 to 2000 feet in height, commanding generally extensive 
views, and unencumbered with the vegetation which presents so 
great an obstacle to the connexion of stations in the more genial 
climates. The access to all parts of the interior is greatly facili- 
tated by the extensive fiords, and arms of the sea, by which the 
land is intersected in so remarkable a manner: these, whether 
frozen over, as in the early part of the season, or open to naviga- 
tion, as in the later months, form routes of communication suited 
to the safe conveyance of instruments either in sledges * or in 
boats ; the fiord, in particular, which separates the western and 
eastern divisions of Spitzbergen, would be of great avail ; it ex- 
tends in a due north and south direction for above 120 miles, with 
a breadth varying from ten to thirty miles, and communicates at 
its northern extremity, by a short passage across the land, with 
the head of another fiord proceeding to meet it from the northern 
shores of the island, and affording similar facilities for carrying 
on either a triangulation, or a direct measurement, on the surface 


* Sledges with rein-deer trained to draft, and the Fins by whom they are 
managed, may be hired for the season, at Mammerfest, in any number that 
might be required. Spitzbergen abounds more in the food of the rein-deer, 
and is more plentifully stocked with the animals themselves in their wild state, 
than any other arctic country which I have visited. The Officers of the Griper 
killed moie than Hfty deer on the small islands which form the northern part 
of the harbour of Fairhavcn. 


154 Captain Sabine on the 

of the ice at the level of the ocean. It is hardly necessary to 
add, that the latter operation would be unembarrassed by the ine- 
qualities of surface, and uncertain temperature of the apparatus, 
which occasion so much trouble, and require so much precaution 
in the usual determination of a base. 

" The extent of the arc in the direction of the meridian, between 
the southern shores of Spitzbergen and the islands on its northern 
coast in the eighty-first degree of latitude, is between four and five 
degrees. At the period of the celebrity of Spitzbergen as a fishing 
station, in the middle of the seventeenth century, when above 
200 vessels, manned by 10 or 12,000 seamen, annually resorted 
to its vicinity, and frequented its harbours for the purposes of 
boiling oil, and when the harbours were divided by convention 
amongst the vessels in consequence of their numbers, according 
to the nation and towns to which they belonged, all parts of the 
coast were known to and visited by the hardy and enterprising 
Dutch and German seamen, by whom the fishery was then princi- 
pally conducted. The whales have long since deserted the haunts 
which their kind had enjoyed for ages before in unmolested secu- 
rity, and have sought retreats less accessible to man ; the graves, 
which occupy every level spot around the harbours, contain the 
only and in that climate the almost imperishable memorials of the 
once busy scene, which has reverted to its original solitude ; even 
the accidental presence of a whaling ship in the western harbours 
is an event of rare occurrence *, and it is probable that more than 
half a century has elapsed since any vessel has passed to the 
North-eastern shores ; it is not surprising, therefore, that the de- 
lineation of land, represented in the charts of the period when 
Spitzbergen was so greatly frequented as existing to the East of 
the seven islands, and to extend in a northerly direction far into 
the eighty-second parallel, should neither have been established 
nor disproved by modern authorities ; those persons who have had 
opportunities of becoming acquainted, by examination on the spot, 
with the remarkable correctness of the older charts in general, in 
the insertion and in the relative position (when not separated by 
much extent of ocean) of lands then recently discovered, will 
hesitate too hastily to reject their testimony, until it has been sa- 
tisfactorily disproved ; should land exist as represented in the 
charts of the period alluded to, even though not visible from 

* During the Griper's stay of three weeks in the neighbourhood of the har- 
bour of principal resort in earlier times, and in the middle of the fishing sea- 
son, not a single whale fish or whaling ship were seen. The only vessels 
which now frequent the shores of Spitzbergen, are Norwegian sloops in quest 
of sea-horses and eider down. Their visits have been hitherto confined to the 
fiords and the islands on the southern and western coasts ; they arrive early 
in March, and remain as late as November, making occasionally three voy- 
ages in a season. 


Figure of the Earth. 155 

Spitzbergen, its triangular connexion might be established on the 
surface of the ice, and latitudes yet unattained be included in the 
operations of the survey ; nor would it be safe to assign too con- 
fidently the northern limit of such operations even in the absence 
of land, in our present ignorance of the facilities which the ice it- 
self may afford for their extension towards the pole. 

" The measurement of a portion of the meridian in the higher 
latitudes is, however, one of the many experimental inquiries, be- 
yond the reach of individual means to accomplish, for which the 
advancement of natural knowledge is delayed ; if its accomplish- 
ment may be hoped for by that nation which has been most for- 
ward in exploring the regions of the north, — to whom its climates 
and its natural difficulties are familiar, — it must still await the 
existence of a channel in one of the departments of the state, 
through which the liberal disposition of the British Government 
to forward every undertaking worthy of a great nation, and by 
which it may occupy an additional page in history, shall be ren- 
dered available to other branches of scientific research, than those 
which are immediately conducive to the interests of navigation. — 
p. 360 — 364. 

There can be no question that the measurement of an arc of 
the meridian of Spitzbergen, of sufficient magnitude to render in- 
consequential the irregularities in the direction of gravitation at 
its extremities, (and such would be an arc of 4| or 5 degrees,) 
would be one of the most important, as well as one of the most 
splendid, of those enterprises for the advancement of general 
knowledge, which from time to time have received the support of 
enlightened governments, and have commanded the admiration of 
all civilized nations. To those persons, to whom the climates of 
the North, and the difficulties presented by its icy seas and 
barren shores, are not as familiar as they are to our author, the 
natural impediments to the accomplishment of such an under- 
taking, may appear in a more serious light than they are viewed 
by him, who has had experience of the means by which they may 
be surmounted, and has himself proved that such extreme situa- 
tions are not incompatible with the utmost accuracy of experi- 
ment. But we do not hesitate to say that the attempt, even if it 
should terminate in demonstrating the impracticability of accom- 
plishment*, would do honour to the government and the country, 

* We are happy to have it in our power to state, that the proposed mea- 
surement of an arc at Spitzbergen, was brought under the notice of the Presi- 
dent and Council of the Royal Society, previously to the last recess; ftnd that 
the propriety of recommending to the Government an undertaking so import- 
ant to the advancement of natural knowledge, is now under consideration. — 
Editor. 


156 Captain Sabine on the 

by which it should be made; and, that there is no country so 
competent to the undertaking as Great Britain ; nor any time so 
suitable as the present; Avhen the experience which she has 
gained in her northern voyages, (which have long since ceased to 
have any more important practical object in view than the acqui- 
sition of such experience, and the cultivation generally of a spirit 
of enterprise,) may be most advantageously applied in the attain- 
ment of a purpose, of the highest rank in the advancement of 
science, and in the general interest of which, the nations of every 
quarter of the globe, and of all succeeding periods will partici- 
pate. It is time that Great Britain, pre-eminent as she is in com- 
mercial enterprise, and in that of maritime and geographical 
discovery, with wealth at command, and a government well- 
disposed to " forward every undertaking worthy of a great nation, 
and by which it may occupy an additional page in history," should 
assert a like pre-eminence, (which she does not at present pos- 
sess,) in enterprises of a higher character, than the mere tracing 
the direction of a river, or the completion of the outline of dis- 
tant, and for any useful purpose, unprofitable shores. 

We proceed to notice, and we shall do so as briefly as possible, 
the bearing of Captain Sabine's experiments upon the application 
of the pendulum as a standard of measure, and upon the experi- 
ments which are previously considered to have referred the 
British linear scale to a definite length in nature. It is in this 
relation that we consider his work as entitled to the greatest at- 
tention, because the pendulum furnishes in all probability the 
only natural standard of measure that is invariable, determinate, 
and easily determinable, and as such it has become the subject of 
legislative enactments, having been adopted in an act passed in 
the session of 1824, and referred to as the means of identifying 
the authentic legal scale of Great Britain : there can be no doubt 
however, after the perusal of Captain Sabine's remarks, in pages 
364 to 372, that the provision made by the act is inadequate for 
the purpose ; and there cannot be a stronger evidence of the im- 
portance of more consideration being devoted to the subject, than 
that the provision of an act, designed expressly for the most dis- 
tant posterity, should thus be shewn to be incompetent to its pur- 
pose, even before the act itself has arrived in operation. The 
act declares the British imperial yard to bear a certain proportion 
to the " pendulum vibrating seconds of mean time in the lati- 
tude of London, in a vacuum at the level of the sea." It neces- 
sarily assumes, consequently, 1st. That the length in nature so 
referred to, is of an uniform magnitude, and 2d, Not only that it 
has been measured, but that all future measurements must con- 
duct to an identical result. 

With respect to the first point, the experiments that are con- 
tained in the present volume shew conclusively that the latitude. 


Figure of the Earth. 157 

of the place and its elevation above the mean level of the sea, 
are not the only, nor even the chief, circumstances, that affect 
the length of the pendulum ; and consequently, that the measure- 
ment in any one place, even supposing it to be correctly made, 
and reduced to the level of the sea, by an amount which should 
not be arbitrarily assumed, does not determine the pendulum of the 
latitude, because the nature and density of the substances, that 
compose the upper crust of the earth at the place of observation, 
have a most important bearing, and which cannot be neglected. 
The clock and the experimental pendulum were found to be liable 
to variations of not less than ten seconds per day in the same la- 
titude, according to the nature of the materials upon which they 
rested ; and, as all the observations were necessarily made upon 
the land, it is inferred that an equal variation in an opposite di- 
rection, might be considered as likely to occur if the experiments 
could be performed at different points on the surface of the 
ocean : the whole difference, then, that might arise from the ac- 
tion of the different substances that are found on the surface of 
the globe may, in the same latitude, amount to no less than twenty 
seconds ; and the difference in the length of the pendulum at sta- 
tions differing in local circumstances, but still under the same 
parallel, might be equal to 0.01 of an inch ; or nearly one-tenth 
of the whole difference of the intensities of gravity at the pole 
and the equator, or to -o-xnro^h part of the absolute attraction of the 
earth. It would thus appear, that before the mean force of gra- 
vity, in any parallel of latitude, can be inferred with certainty, 
numerous observations, indeed an almost indefinite number, ought 
to be made in or near that parallel, to produce by their combina- 
tion, a near result. 

With respect also to the allowance to be applied to the length 
of a pendulum measured at an height above the sea, to reduce it 
to what it would have been if measured at the level, it is shewn 
that the correction which has been recently proposed, for the 
error arising from the figure of the surface, by which the regular 
decrease of gravity in proportion to the squares of the distances 
from the centre is affected, may be safely neglected ; but that a 
far greater uncertainty than from external conformation, and for 
which it would be far more difficult to assign a specific correction, 
is involved by the variable density of the materials, on which the 
pendulum is raised above the surface of the sea. From these 
considerations, Captain Sabine concludes that the pendulum of a 
particular latitude cannot become a standard of reference, because 
its length is not practically determinable ; that the pendulum of 
a particular city, London for example, (whereby it is implied that 
a length measured in one part of the city should be recoverable 
by a measurement made in some other part of the city,) is open 
to the same objections, though in a le.ss degree ; but that the more 


158 Captain Sabine on the 

simple standard, and which is of determinate and determinable 
magnitude, is the pendulum of a particular spot ; it being under- 
stood that all future repetitions, designed to produce identical re- 
sults, should be made identically at the same place. 

We consider, that Captain Sabine has gone far towards proving 
that, in this view, the pendulum is applicable to the proposed ob- 
ject ; that with proper precautions, and by adopting the method 
of experimenting which he has pointed out, different observers, 
using different instruments, may arrive with certainty at identi- 
cal conclusions : at least so nearly identical as not to differ in the 
fourth place of decimals of a British inch. But he has also 
shewn (pages 213 to 233,) that the method which was previously 
adopted, and employed in the experiments which are considered 
by the act of parliament to have determined the length of the se- 
conds pendulum in the latitude of London, does by no means en- 
sure identity on repetition within the limits declared in the act ; 
because the method is not independent of individual peculiarity, 
or of accidental circumstance. The conviction is thus forced 
upon us, of how essential the experiment itself of repetition is ; 
and that it is expedient to prove that a method will produce iden- 
tical results in other hands than the original experimenter, before 
it is officially bequeathed for such purpose to posterity. 

The selection of a spot, the pendulum of which is to supply an 
invariable length in perpetuity, and which will require to be re- 
ferred to, not less by foreign nations of the present day, who may 
desire to compare their standards with that of Great Britain, 
than by those of more distant ages who may seek the recovery of 
the British measures, is by no means an indifferent consideration, 
It has happened accidentally that the original experiments were 
made in a private house in London : a circumstance which in it- 
self, must sooner or later have obliged their repetition elsewhere. 
But if the length of the pendulum is affected by natural local 
circumstances, to the amount we have stated, (and we think the 
fact too clearly made out by Captain Sabine to be questioned,) may 
not even artificial changes in the character of the place of experi- 
ment produce a similar result, although in a less degree ? Can 
we be assured that the vibrations of a pendulum, in Mr. Browne's 
house in Portland Place, are the same now, as when, not more 
than two centuries ago, its site was nearly a mile without the 
limits of the city ? Nor are either of these times identical with 
that which would be found, were the future observer compelled to 
seek for the spot amongst masses of rubbish. Nor is this last 
view of the subject, however improbable or distant, one that is to 
be entirely neglected. The language, the arts, and the sciences, 
which are the boast of Great Britain at the present day, are founded 
upon a basis more secure than that of empire, and will exercise an 
intellectual supremacy over future ages, should even the fate that 


Figure of the Earth. 159 

has attended the former " glories of the world," overwhelm, at; 
some remote period, her proud metropolis. It must ever be re- 
membered, that on the transmission of her scale, will depend the 
value to posterity of eveiy attainment which she either has made, 
or may make, in which linear measure is concerned; and that con- 
sequently her fame and her usefulness in those distant times may 
materially be influenced by the provision which she may now 
make for its exact transmission. 

For these, and for other reasons which we have not space to 
state, we should consider it highly expedient that, whenever 
Kater's original experiments shall be repeated, for the final veri- 
fication of the British scale, the proceedings should take place in 
a public building, and at such a distance from any probable exten- 
sion of dense population, as may secure a close resemblance to 
its present state for centuries ; and that, when the pendulum of 
that spot shall be considered as fully and satisfactorily deter- 
mined, other nations, which may be disposed to adopt a simi- 
lar proceeding, should be invited to a direct comparison of the 
standards and measurements of the respective countries, not only 
for the more perfect assurance of accuracy, but in order that the 
places may be multiplied on the globe, at which the British mea- 
sures may be hereafter reproducible. 

"We perceive that we have already attained our limits in the ex- 
amination of the subjects contained in little more than half the 
work before us : the remainder consists of geographical, hydro* 
graphical, and magnetic notices of great interest, particularly the 
latter : the subjects however are distinct, and require in fact to 
be treated of separately ; we shall not, therefore, however worthy 
they may be of notice, trespass further on the patience of our 
readers ; but shall conclude with recommending its perusal to all 
persons who take an interest in such investigations, as one of the 
ablest works with which we are acquainted. 


III. Remarks on Professor Spohn's Essay De Lingua et Liter is 
Veterum ^Egyptiorum, edited by Professor Seyjfarili, 4io. Leip- 
zig, 1 825. In a Letter to Baron William von Humboldt. 

My Dear Sir, 

I have to thank you for the favour of your letter sent me 
by Mr. Struve : I have delayed making this acknowledgment, until 
I could return you some answer on the subject of Mr. Spohn, whose 
posthumous work you mention as having engaged your attention. 
We might suppose it to be almost impossible that a man possessed 
of any talents should spend some years of his life in a field of lite- 


160 Remarks on Spohn's Essay. 

rature not wholly barren, without obtaining some few fruits of his 
labour, which had escaped the researches of others ; but I have 
looked in vain for any one addition to what even Mr. Akerblad 
had made out, more than thirty years ago, that can justify the 
pomp and ceremony with which Professor Seyffarth's Prodromus 
is issued into the world. 

The most satisfactory evidence on this subject is that of the 
papyrus of Casati, which I discovered to be the original of Mr. 
Grey's Greek antigraph, a little after I had printed, and distributed 
among a few friends, my attempt to translate some parts of the 
original, which appeared in the Philosophical Journal for January, 
1 823. You will find in it Nebonenc/tws as a proper name, twice 
over ; Apollonius, Antimachus, and Antigenes : the three last 
having been read nearly in the same manner by Champollion. 
There is also a phrase, et liberis ejus, hominibus ejus, frequently 
repeated. 

Of these, Professor Spohn has made out the letters nebonen, 
and etplonies, without marking them as proper names ; and he has 
put down Antimaus and Antigenes as a part of his translation : 
but he has not attempted any explanation of the phrase, which is 
repeatedly rendered in the antigraph, xoiih his children and all his 
family, nor has he rightly translated a single word besides, after 
the preamble, which is not in the Greek. 

With respect to his mode of reading the words, by an alphabet, 
which, the newspapers tell us, is like the Armenian, this manu- 
script affords an undeniable criterion of its accuracy, as it con- 
sists almost entirely of proper names, originally Egyptian, not 
one of which has been read by Professor Spohn in any way at all 
approaching to the truth. For example, instead of Maesis Mir- 
sios, he gives us Eumolme Nnelleme ; for Peteutemis Arsiesios, 
Ischre pepo eepo nenee ; and for Petearpocrates Hori, Nearsch- 
neoe hne. If his Egyptian dedication to the King of Saxony is 
equally happy with these specimens, it may happen to pass current 
in the other world for an address to Sesostris or to Osiris himself, 
or for a confession of faith in all the gods and goddesses of Ombos 
and of Tentyra; and thus to have procured him admission into the 
blessed communion of those deified Egyptian kings, who are occa- 
sionally represented, according to Mr. Bankes's drawings, as offer- 
ing sacrifices to themselves. 

London, 22 Sept. 1825. * * * 


161 


Art. XVI. MISCELLANEOUS INTELLIGENCE. 

I. Mechanical Science. 

1 . Dr. Black's Sensible Balance. — The following description of 
a very delicate and, to many it may be, very useful balance, is 
taken from a letter written by Dr. Black, to James Smithson, 
Esq., and inserted in the Annals of Philosophy, N. S. x. 52. " The 
apparatus I use for weighing small globules of metals, or the 
like, is as follows : A thin piece of fir-wood, not thicker than a 
shilling, and a foot long, 3-10ths of an inch broad at the middle, 
and lj tenths at each end, is divided by transverse lines into 20 
parts, i. e. ten parts on each side of the middle. These are the 
principal divisions, and each of them is subdivided into halves 
and quarters. Across the middle is fixed one of the smallest 
needles I could procure, to serve as an axis, and it is fixed in its 
place by means of a little sealing-wax. The numerations of the 
divisions is from the middle to each end of the beam. The ful- 
crum is a bit of plate-brass, the middle of which lies flat on my 
table when I use the balance, and the two ends are bent up to a 
right angle, so as to stand upright. These two ends are ground 
at the same time on a flat hone, that the extreme surfaces of them 
may be in the same plane ; and their distance is such that the, 
needle, when laid across them, rests on them at a small distance 
from the sides of the beam. They rise above the surface of the 
table only one and a half or two-tenths of an inch, so that the 
beam is very limited in its play. 

«' The weights I use are one globule of gold, which weighs one 
grain, and two or three others which weigh one-tenth of a grain 
each ; and also a number of small rings of fine brass wire, made 
in the manner first mentioned by Mr. Lewis, by appending a weight 
to the wire, and coiling it with the tension of that weight round a 
thicker brass wire in a close spiral, after which the extremity of 
the spiral being tied hard with waxed thread, I put the covered 
wire in a vice, and applying a sharp knife, which is struck with a 
hammer, I cut through a great number of the coils at one stroke, 
and find them as exactly equal to one another as can be desired. 
Those I use happen to be the one-thirtieth part of a grain each, or 
300 of them weigh ten grains ; but I have others much lighter. 

" You will perceive that by means of these weights, placed on 
differents parts of the beam, I can learn the weight of any little 
mass, from one grain, or a little more, to the -j? 1 ^ of a grain. For 
if the thing to be weighed weighs one grain, it will, when placed 
on one extremity of the beam, counterpoise the large gold weight 
at the other extremity. If it weighs half a grain, it will counter- 
poise the heavy gold weight at five ; if it weighs 6-10ths of a 
Vol. XX. M 


162 Miscellaneous Intelligence. 

grain, you must place the heavy gold weight at five, and one of the 
lighter ones at the extremity to counterpoise it ; and if it weighs 
only 1, or 2, or 3, or 4-100ths of a grain, it will be counterpoised 
"by one of the small gold weights placed at the first, or second, or 
third, or fourth division. If, on the contrary, it weigh one grain 
and a fraction, it will be counterpoised by the heavy gold weight 
at the extremity, and one or more of the lighter ones placed in 
some other part of the beam. 

" This beam has served me hitherto for every purpose ; but had 
I occasion for a more delicate one, I could make it easily by taking 
a much thinner and lighter slip of wood, and grinding the needle 
to give it an edge. It would also be easy to make it carry small 
scales of paper for particular purposes." 

Mr. Smithson observes, that the rings, or small weights, men- 
tioned above, have the defect of their weight being entirely acci- 
dental, and consequently most times very inconvenient fractions 
of grains, and recommends instead that the weight of a certain 
length of wire be ascertained, and then the length of it taken, 
which corresponds to the weight wanted ; when fine wire is used, 
a set of small weights may thus be made with great accuracy and 
ease. This is a process, the value of which is well known to the 
philosophical instrument maker. 

2. Tenacity of Iron, as applicable to Chain-Bridges. — The fol- 
lowing results have been deduced from experiments made in Rus- 
sia, and detailed by M. Lamb, in a letter from Petersburgh, Ann. 
des Mines, x. 311. In the apparatus contrived for the purpose the 
power was applied by a hydraulic press. 

The best iron tried supported 26 tons per square inch, without 
being torn asunder. The bars began to lengthen sensibly when 
two-thirds of this power had been applied, and the elongation 
appeared to increase in a geometrical ratio with arithmetical in- 
crements of power. The worst iron tried, gave way under a ten- 
sion of fourteen tons to the square inch of section, and did not 
lengthen sensibly before rupture. By forging four bars of iron 
of medium quality together, an iron was obtained which did not 
begin to lengthen until sixteen tons had been applied, and sup- 
porting a weight of twenty-four tons without breaking. 

Taking these results as sufficient data, it was decided by the 
committee appointed for the purpose, that the thickness of chains 
in a suspension bridge should be calculated so that the maximum 
weight to be borne should not exceed eight tons per square inch 
of sectional surface, and that before being used they should be 
subjected to a tension of sixteen tons per square inch, and bear it 
without any sensible elongation. 

3. Moving Rocks of Salisbury. — Inconsequence of the interest 


Mechanical Science. 1 G3 

attached in America to the phenomena of moving rocks, described 
in a former page of the Journal *, Mr. C. A. Lee, who first called 
attention to them, was induced to examine them more minutely, and 
by noticing their situation and appearance accurately both before and 
after winter weather, ascertain decidedly the cause of their trans- 
portation. He says, " being fully convinced that the rocks were 
moved by the agency of the ice, in the month of December 1823, 
I took the distance of one of the largest to a tree on the shore. 
In the month of January 1824, there were several very cold 
nights, during which the ice was heard to roar not unlike the dis- 
charge of a cannon. I visited the spot immediately after, and 
was no longer in doubt respecting the true cause of the movement 
of the rocks. On most of them the ice was piled up several feet 
in height, projecting from the side of the rock next to the main 
body of the ice, towards the shore. Some which did not oppose 
so strong a resistance were evidently displaced, and the one in 
particular which I measured was moved several inches, although 
very firmly fixed in the stones and gravel. During the past win- 
ter the rocks have moved but very little, owing to the mildness of 
the season. From Dec. 1823, to Feb. 1825, the rock above men- 
tioned has moved two feet and a half, which is much less than in 
former years, for the same reason ; besides, it has now become 
more deeply imbedded in the gravel, and the full force of the ex- 
panding ice is not exerted upon it." 

Mr. Lee, who dates from Salisbury, says, that since the first 
notice taken of them in 1822, the effect and the cause have been 
recognised in many places, and by many persons, and that no 
doubt now exists as to either. In the mountain pond of Salis- 
bury, the rocks within reach of the ice are annually moved towards 
the shore, and have formed an artificial dyke of considerable extent. 
He objects to Mr. Wood's explication founded upon the carrying 
power of the ice, and states correctly that the ice generally melt$ 
first around the rocks ; which are in this way soon loosened from it 
on the occurrence of a thaw. — Silliman's Journ. ix. 239. 

; 

4. Etruscan Vases. — The following are the conclusions arrived 
at by Professor Hausman, during an inquiry into the composition 
of these vases : 1. That the manufacture of earthen vases, appro- 
priated to funeral occasions, had been widely propagated at a re- 
mote period of antiquity, with little deviation from a general plan, 
in so far as regards their principal circumstances. 2. That these 
vases have been formed with much particular diversity in regard 
to less important circumstances, such as the quality of the clay 
employed, and differences in the forms, ornaments, and paintings, 
not only in different countries and at different times, but also in 

* Vol. \\x. p. 868. 
M 2 


164 Miscellaneous Intelligence. 


O" 


the same countries and at the same period. 3. That the finer sort 
of these vases are superior in regard to the preparation of the 
clay, and the elegance and variety of the forms, as well as the care 
of the paintings, to all others of the kind, whether of Roman or 
of modern manufacture, insomuch that the pottery of the most 
remote ages forms the model of that of the present times. 4. That 
the art of manufacturing these vases, as practised in very remote 
times, is much more worthy of estimation than our best perform- 
ances in that way, since the ancients were not in possession of 
many assistances which are applied to the art by us ; and because 
some things which are now done without difficulty, by means of 
certain instruments or machinery, were, in those times, perfected 
by means of the hand alone, by the greater dexterity of the artists. 
5. That certain circumstances were peculiar to the very ancient 
arts of making and ornamenting those earthen vessels which have 
evidently been lost in later times, of which may be mentioned in 
particular the composition of a very thin varnish, which gave a 
heightening to the colour of the clay in a greater or less degree, 
and afforded a very thin firm black coating, retaining its lustre to 
the most remote ages, and capable of resisting the action of acids 
and other fluids ; so that the modern art of manufacturing pottery 
ware may be materially improved, not only with regard to the 
forms and ornaments, but also the preparation and application of 
the materials, by a diligent and continued examination of those 
very ancient vases. — Edin. Phil. Journ. xiii. 62. 

5. On the Repulsion exerted by Heated Bodies at sensible Distances. 
By M. A. Fresnel. — M. Libri published last year, in an Italian 
Journal, some curious experiments on the motions of a drop of 
fluid suspended on a metallic wire, of which one extremity was 
heated : he observed that the drop always receded from the source 
of heat, even when a very sensible inclination was given to the 
wire. This phenomenon may be explained by the changes in the 
capillary action of the solid surface and the liquid, caused by the 
elevation of temperature, and which will be different at the un- 
equally heated extremities of the drop. It may also be admitted 
(which is the same thing) that the molecules repel each other more 
powerfully as their temperature is higher. According to this hypo- 
thesis, each liquid molecule in contact with the metallic wire will 
be more repelled by the small portion of surface on the side to- 
wards the source of heat, than by the contiguous portions, from 
which would result a sum of many small actions, all tending to 
impel the drop from the heated extremity. 

In neither of these methods of viewing the phenomenon is it 
necessary to suppose that the reciprocal action of the molecules 
extends to sensible distances ; but some other experiments of M. 
Libri on the same subject appears, as hs has observed, to indicate 


Mechanical Science. 165 

repulsion at a distance. Nevertheless, I dare not affirm that they 
establish this mode of action, though I have observed its existence 
in another manner, because the calorific repulsions for intervals of 
some millimetres are so feeble that I can hardly believe them ca- 
pable of overcoming the friction of the drop of liquid on the wire. 

I had uselessly endeavoured, for a long time, for the verifica- 
tion of certain hypotheses, to move a small disc of foil attached to 
the extremity of a very light horizontal stem, supported by a 
thread of silk in vacuo, by the action of the solar rays collected 
together by a lens. Since then I proposed to try whether this 
mobile disc would not be repelled by a heated body brought near 
to it ; but I should no doubt have delayed the execution of this 
project, if M. Libri had not communicated to me his interesting 
observations. They, by inducing me to consider the success as 
probable, caused me the sooner to make the experiment. 

For its convenient performance a very fine steel wire, mag- 
netized, and suspended by a silk fibre, had attached to its extre- 
mities a disc of foil, and a disc cut from a plate of mica, for the 
purpose of trying an opaque and a transparent body in the same 
apparatus : the fixed body, intended to repel the balance of torsion 
was also a disc of foil. A vacuum was carefully made within the 
glass jar which enclosed the apparatus ; the elasticity of the re- 
maining air indicated by the mercurial gauge was not more than 
one or two millimetres. The jar was then placed in the sun's 
rays, and so turned that the magnetized steel wire was but little 
out of the magnetic meridian, yet sufficient to cause one of the 
discs fixed at its extremity to exert a very slight pressure against 
the fixed disc, so that it should remain in contact with it. The 
apparatus thus arranged, I threw the sun's rays by a lens, some- 
times on the fixed disc, sometimes on the moveable one, and im- 
mediately the latter separated quickly from the former. I re- 
tained it separate, and sometimes at the distance of a centimetre, 
(0.39371 of an inch,) by continuing to heat the discs. When I 
removed the lens, the balance of torsion did not return imme- 
diately to the fixed body, but gradually approached it, performing 
small oscillations. It is very probable that if I had employed 
thicker bodies, and such as would cool more slowly, the return to 
the original position would have been more gradual. 

It seemed to me as if the transparent disc was not so strongly 
repelled as the disc of foil. I observed also that the most ad- 
vantageous manner of heating the bodies, so as to retain them at 
the maximum distance, was to send the focus of the lens on to one 
of the opposing surfaces. I do not suppose that this effect is due 
to reflection, but merely to the facility obtained in this way of 
more highly heating the surface which is to exert the repulsive 
action. 

That I might be assured these phenomena were not occasioned 


166 Miscellaneous Intelligence, 

T>y the small quantity of air or vapour remaining in the bell-glass, 
I let the air re-enter gradually ; and on repeating the experiment 
when the internal air was fifteen or twenty times denser than at 
the commencement, I found that the repulsion had not sensibly 
augmented in energy, as should have happened had it been occa- 
sioned by the motion of the heated air. There were, indeed, cer- 
tain positions of the mobile disc relative to the fixed one in which 
the divergence was not so great as in vacuo. 

I tried whether the interposition of an opaque screen, composed 
of two plates of foil separated by a small interval, intercepted the 
repulsive action of the fixed disc on the mobile one when either of 
them were heated ; it appeared to me that the screen prevented 
repulsion. But does it entirely intercept the action ? is a question 
difficult to answer in this way ; for the interposition of the screen 
so that the heat should not be too rapidly communicated to it, in- 
cludes the necessity of a considerable interval between the fixed 
and mobile discs. 

In consequence of the directive force which tends to replace the 
steel wire in the magnetic meridian, the apparatus I have described 
will serve to measure the calorific repulsion of two bodies at dif- 
ferent distances. With it also may be made other interesting ex- 
periments. I should have been desirous that this note presented 
such results that it might have been more worthy of presentation 
to the Academy ; but the experiments require time, and are labo- 
rious, inasmuch as the vacuum has to be re-formed each time the 
apparatus is changed. I hope that philosophers, more expert, or 
more at leisure, will not disdain to join in these researches, which 
promise new and curious results, and may, perhaps, throw light 
on the theory of the dilatation of bodies by heat. 

P. S. To complete this note I should add my reply to the ob- 
jection of an illustrious geometer, who inquired if I was certain 
that the phenomena of repulsion which I had described to the Aca- 
demy were not due to electricity developed by the heat. In my 
apparatus the metallic stem of the fixed disc communicated with 
the earth by the copper tube which passed through the glass plate 
on which the jar stood ; so that if by throwing the focus of solar 
rays on to the mobile disc it had been rendered electrical, it would 
always have been attracted instead of repelled by the fixed disc. 

Neither can we suppose it more probable that the phenomena 
depend on a magnetic action ; for if by throwing the focus on to the 
fixed disc it became magnetic, it would certainly have repelled 
one of the extremities of the steel wire ; but it would have at- 
tracted the other ; whilst, in fact, it equally repelled the two ge- 
nerally : a constant repulsion in varied and even opposed circum- 
stances excludes the supposition of an electric or magnetic action. 

On repeating the above experiments with thicker discs, it did 
not appear that the repulsive force was sensibly augmented. If 


. Mechanical Science. 167 

4his observation be supposed correct, and the temperatures equal 
in the two cases, it may be concluded that the force which causes 
deviation of the magnetic needle depends upon the extent of sur- 
face only, and does not emanate from all the particles comprised 
in the thickness of the heated disc. By trying bodies of different 
kinds, and especially those which are transparent, and varying 
also in thickness, it will, perhaps, be possible to determine to 
what degree they intercept the repulsive action, arising from ele- 
vation of temperature. 

" When the mobile disc is of some thickness, and its external 
surface is heated, it often happens that it remains for a long time 
in contact with the fixed disc, and separates from it on withdraw- 
ing the lens. This is probably occasioned by the great difference 
of temperature between the two surfaces of the mobile disc, from 
which it may result that the surface receiving the solar rays, is as 
much repelled by the surface of the bell-glass, as the other sur- 
face is by the fixed disc. This I offer only as a doubtful expla- 
nation, not having had time to verify it by new experiments. 

M. Fresnel afterwards says, " new experiments have shewn me 
that the explanation at the end of the note, of the particular phe- 
nomena of thick discs cannot be admitted ; for in that case the 
face of the mobile disc heated by the sun's rays would suffer a 
sensible repulsion from the neighbouring surface of the bell-glass, 
and by throwing the focus of the lens on to the moveable disc 
away from the fixed one, the needle should be deviated ; this, how- 
ever, does not happen. 

With pieces of copper of a hundredth part suspended from the 
extremities of the magnetic steel wire, I have obtained very ap- 
parent effects of attraction. When the solar rays were thrown on 
the exterior face of the mobile disc near to the fixed disc, it ap- 
proached and adhered to it as if attracted. This attraction was 
not occasioned by a developement of electricity, for the solar rays, 
reunited on the other mobile disc, produced no sensible effects, 
though the two suspended discs were connected by the steel wire. 

I have observed actions similar to these in many other circum- 
stances, but I have as yet too slightly studied these singular phe- 
nomena to give a general and exact description ; I can only say 
that the experiments I have thus far made confirm me in the 
opinion that both the attractions and repulsions, produced by heat, 
do not arise from the developement of electric tension ; and if they 
belong to a momentary state of emanation of the heated discs, it 
appears to me at least that the distribution of magnetism here 
follows particular laws. — Ann. dc Chimie, xxix. 57, 107. 

6. Polarized State of Halo Light. — M. Arago announced to the 
Academy, that upon examining a halo round the sun towards 
eleven o'clock in the morning, with an instrument of his inven- 


168 Miscellaneous Intelligence. 

tion, he remarked very unequivocal traces of polarization hy re- 
fraction in the light of which the halo was formed. This experi- 
ment excludes all explications of the phenomenon founded upon 
the hypothesis of a reflexion. M. Arago thinks that the instru- 
ment he made use of in this observation will enable him more ge- 
nerally to ascertain when a cloud is frozen, and that it will then 
supply the means of studying the law of the diminution of heat in 
the atmosphere. — Ann. de Chimie, xxix. 77. 

7. Nature of Shooting Stars seen during Day-Time. — An account 
Iby Professor Hanstein of a shooting-star seen in the day-time, has 
recently attracted some little attention*. Mr. Dick, however, 
doubts the assigned nature of the appearances, and states reasons 
for concluding it to be nothing more than a bird. Whilst making 
observations twelve years ago on Venus, when close to the sun, 
he, whilst looking for the planet, remarked a body passing across 
the field of the telescope, apparently of the size of Venus, but 
varying a little in this respect ; at first it was mistaken for the 
planet, but its rapid motion corrected the error. In some instances 
four or five of these bodies appeared to cross the field of view, 
sometimes in a perpendicular, and at other times in a horizontal 
direction. They appeared to be luminous bodies somewhat re- 
sembling the appearance of a planet, when viewed in the day- 
time with a telescope of moderate power. Their motion was rapid, 
and inclined to a waving or serpentine form. After twelve months' 
observation, Mr. Dick was enabled, by observation of some which 
were larger than others, to decide they were birds, whose bodies, 
illuminated by the solar rays, reflected light enough to produce 
the appearance. In a hot summer's day, when a similar pheno- 
menon has been observed, there was every reason to attribute it 
to a number of winged instruments flying at no great distance 
from the telescope. 

Mr. Pick observes that Professor Hanstein's account of the kind 
of motion as being unequal, and resembling that of a rocket, cor- 
responds to the motion of birds through the air. He remarks too, 
that an appearance observed by the late Mr. B. Martin, of certain 
bright round bodies running towards the sun, when viewed in 
particular circumstances, may be explained in the same manner. — 
Edin. Phil. Journal, xiii. 167. 

8. Astronomical Prize Question. — " Method of calculating per- 
turbations of the elliptical motion of comets, applied to the deter- 
mination of the approaching return of the comet of 1759, and to 
the motion of that observed in 1805, 1819, and 1822." The prize 
a gold medal of 3000 francs value. Memoires received till Jan. 1, 
1826, — Royal Academy of Sciences, Paris. 

* Quarterly Journal, Vol. xix. p. 369, 


Chemical Science. 169 

9. Prize Question ; Natural Philosophy. — 1. " ( To determine by 
numerous experiments the density acquired by liquids, and espe- 
cially mercury, water, alcohol, and sulphuric ether, by pres- 
sures equivalent to the weight of many atmospheres. — 2. To 
measure the effects of heat produced by these compressions." 
The prize a gold medal of three thousand francs value. Memoires 
received tillJan. 1, 182G. Royal Academy of Sciences, Paris. 

II. Chemical Science. 

1. On the Dry Voltaic Piles of M. Zamboni. — The following is 
part of a report made by M. Ampere, on a memoir relative to the 
above voltaic combinations. 

The energy of these dry piles ceases to diminish after two 
years ; such, at least, M. Zamboni finds to be the case during 
twelve years' experience. 

The diminution in the two first years varies according to the 
manner in which the pile is constructed. 

The pile is more energetic in summer than in winter, both with 
regard to the intensity produced, and the promptitude with which 
it is manifested. 

The tinned paper, called silvered paper, with black oxide of 
manganese, developes an electric force very superior to that ob- 
tained when the paper is covered witli a thin leaf of copper ; the 
latter is known under the name of gilt paper, (Dutch gold 
paper.) 

A pile formed of discs of paper, tinned on one side, without 
any interposing substance, produces electrical effects, which can 
result only from the circumstance that the metallic leaf, glued 
to the upper surface of the paper, touches it more intimately than 
it does the lower surface of the paper belonging to the element 
next placed above. 

M. Zamboni has examined whether in those piles, which he 
calls binary, the action of the elements takes place as in those 
which are composed of leaves of tin, covered with oxide of man- 
ganese, or in the reverse order. He found that one or the other 
of these results could be obtained at pleasure, by imbibing the 
paper attached to the tin, with various substances. When oil 
was used the action was opposed to that produced by oxide of 
manganese ; when, on the contrary, the paper was imbibed with 
honey or alkali, a solution of sulphate of zinc, or milk in a 
semi-coagulated state, the binary pile acts like those composed 
of elements powdered with oxide of manganese. 

By using a dry pile of 1000 pairs, the plates not being more 
than five or six centimetres, (from two to two and one-third of 
an inch,) in diameter, M. Zamboni obtained by the condenser 
sparks of an incli in length, so that with such a pile an electric 


170 Miscellaneous Intelligence, 

battery might be retained, constantly charged to a state of ten- 
sion, which might be heightened at pleasure, by increasing the 
number of plates. 

M. Zamboni thinks that a pile of 50,000 pairs of plates, of 
the usual diameter of leaves of tinned paper, would be a con- 
stant source of electricity, of which the tension would equal that 
of a strong common electric machine. He promises that such 
an instrument shall be constructed, and mentions many inte- 
resting experiments to which it may be applied. — Ann. de Chim. 
xxix. 198. 

2. Neiv Galvanometer, by Nobili. — The construction of this 
instrument is founded upon the fact discovered by (Ersted, the 
deviation of a magnetic needle by a wire conveying a current of 
electricity ; and as in most other instruments of this kind, the 
wire is passed several times round the frame, within which the 
needle is suspended, that the effect may be proportionally increased. 
It differs, however, from all made before it, in the use of two 
needles instead of one ; these are equal in size, parallel to each 
other, magnetized in opposite directions, and fixed on a straw, 
so that the contrary ends of the two needles point in the same 
direction. Their distance from each other on the straw is regu- 
lated by the construction of the frame with its covering wire, in 
and about which they are to move. The frame of M. Nobili is 
twenty-two lines long, twelve wide, and six high. The wire is 
of copper covered with silk, it is one-fifth of a line in thickness, 
from twenty-nine to thirty feet long. It makes seventy-two re- 
volutions about the frame. The needles are twenty-two lines 
long, three lines wide, a quarter of a line thick, and they are 
placed on the straw five lines apart from each other. An aper- 
ture is made in the tissue formed by the turns of the wire on the 
upper surface of the galvanometer, by thrusting them from the 
middle towards each side ; the lower needle on the straw is intro- 
duced through this aperture into the interior, in consequence of 
which the upper needle remains a little above the upper surface 
of the wire. The aperture is retained open to a certain extent, 
to allow freedom of motion to the needles and straw, these being 
suspended in the usual way from the upper extremity of the straw. 
The graduated circle on which the deviation is measured is placed 
over the wire on the upper surface of the frame having an aper- 
ture in its centre for the free passage of the needle and straw. 
The upper needle is the index, the lower being visible only from 
the sides of the instrument. 

The sensibility of this instrument depends upon the addition 
of the upper needle. Being magnetized in an opposite direction to 
the lower one, it almost entirely neutralizes the influence of ter- 
restrial magnetism, leaving only so much of directive power as 


Chemical Science. 171 

shall induce the whole arrangement to return to a constant posi- 
tion when uninfluenced by electrical currents, and yet combining 
with the lower needle, to cause deflexion when an electrical cur- 
rent is passing through the wire. 

As an illustration of the delicacy of the instrument M. Nobili 
observes, that it is well known if Seebeck's combination of anti- 
mony and bismuth be attached to a common galvanometer, and 
the point of junction be cooled, only a very slight effect is ob- 
served on the instrument ; whilst, if attached to the new galva- 
nometer, the same influence is sufficient to make the needles re- 
volve several times. If a piece of iron wire, five or six inches long, 
be used to connect the extremities of the copper wire of the in- 
strument, by twisting the ends together, and one of the points 
of contact be warmed by touching it with the hand, the needle 
will move from 0°, and in the first oscillation extend to 90°. 
Even the mere approximation of the hand to the junction of the 
metals will produce a deviation of 20°. 

It is necessary for the delicacy of the instrument that the 
needles used be magnetized as nearly as possible to the same 
degree, and two indications have been observed as useful in point- 
ing out when this is the case ; the first is the position taken up 
by the plane of the needles, when left to the earth's influence ; 
this should not be in the plane of the magnetic meridian, but 
more or less inclined to it ; the second is the manner in which 
the system oscillates about its line of equilibrium. These oscil- 
lations should be very slow compared with those of a common 
needle. 

In consequence of the situation of the graduated circle above, 
and not within the frame, the folds of the wire may be brought 
much nearer to each other than in the common instrument ; this 
renders it more compact, and from the vicinity of the needle 
within to the wire, also more powerful. When fixing the gradua- 
tion, the zero should be placed so as to accord with the position of 
the needles, when left to the earth's influence ; this will not be 
towards the true magnetic north, but will not be far from it, 
and will always be constant. 

M. Nobili then offers a very curious illustration of the powers 
of the instrument : — " It is known," he says, ** that water 
usually retains itself at a lower temperature than the ambient 
air, the difference being sometimes two degrees, and resulting 
from the evaporation of the liquid. If a bar of bismuth be 
made to join the two extremities of the galvanometer wire, and 
one of the points of junction be plunged into a cup of water, 
the needle will immediately deviate several degrees, proving that 
the instrument is capable of measuring the small degree of re- 
frigeration, produced by the evaporation of the liquid. I have 
actually submitted one of my galvanometers for fifteen days to 


172 Miscellaneous Intelligence. 

an experiment of this kind, the deviation was about 15° in the 
morning and evening, but more considerable in the course of the 
day* This first attempt has made me suppose that the galvano- 
meter might become, in the hands of an attentive and skilful 
philosopher, a kind of atmidometer. If by means of a single 
couple of two different metals, bismuth and copper, a deviation 
of 15° has been obtained, a much greater one would be produced 
by employing several pairs, conveniently immersed in the same 
vessel of water ; and, perhaps, one might succeed by increasing 
the scale of observation, in ascertaining more exactly the diurnal 
rate of evaporation. I propose, also, to ascertain the effect of a 
current of air, excited by any means over the surface of the 
water used in the experiment ; it would, without doubt, augment 
the evaporation, and by increasing the difference between the 
temperature of the air and the water, increase the effect on the 
instrument. — Bib. Univ. xxix. 119. 

3. On the Length of the Electric Flash producing Lightning. By 
M. Gay Lussac. — The length of the flash during storms is always 
very great, and one may readily ascertain, in a mountainous 
country, that it frequently exceeds a league. This extraordinary 
length, and the awful sound produced by the flash, induces us 
naturally to admit, that the quantity of electricity which forms it 
is incomparably greater than that which may be accumulated in 
the largest electric batteries. We cannot produce explosion ex- 
cept at the distance of a few centimetres, (an inch or two,) and the 
intensity which we must suppose is required in batteries to make 
an explosion at the distance of a few metres, (or a few yards,) 
only, would be so great as to make it impossible it could be re- 
tained on a coated surface by the pressure of the air. On the 
other side, when lightning falls on a lightning-rod, it frequently 
happens that only a small portion of the point, perhaps three or 
four millimetres, (0.12 to 0.16 of inch,) is fused; and this effect 
is not very different to what may be produced by large electrical 
batteries. 

But we cannot really judge of the intensity of electricity ac- 
cumulated on our conductors, and on a thunder-cloud by the 
length of the spark. The electricity is retained on our conductors 
by the pressure of the air, the spark only occurs when this pres- 
sure can be overcome by the electricity. On the contrary, the 
electricity is retained on a cloud only by the resistance it affords 
to it as a non-conducting body, and equally pressed as it is by 
this fluid which surrounds it on all sides, it should obey the 
slightest attractive or repulsive forces by which it is affected. 
We may therefore conceive, that as soon as the electricity has 
formed a stratum, no matter how attenuated, so that it be con- 
tinuous, the flash may occur and pass through considerable dis- 


Chemical Science. 173 

tances. The intensity of the flash will be produced by the quan- 
tity of electricity contained in the immense stratum enveloping 
the cloud. If the stratum is not continuous, which is very pos- 
sible in so bad a conductor as a cloud, or if all the electricity 
spread over the space occupied by the cloud has not had time to 
disengage itself, so as to arrive at the surface of the cloud, the 
discharge will only be partial, and then the redoubled peals of 
thunder will easily be understood. It appears impossible to us, 
according to these observations, that the thickness of the electric 
stratum can ever be any thing like so great on the surface of a 
thunder cloud as on that of a solid conductor ; for the repulsion 
of its molecules would dissipate it in the air. We perceive no- 
thing to retain it but the resistance of the air as a non-conductor, 
and that resistance can be but very small. 

As the primitive electricity spread over the space occupied by 
a thunder-cloud can unite but very slowly into a thin stratum, it 
becomes difficult, according to the theory of Volta, to attribute 
to it the formation of hail in particles as large as those which are 
sometimes observed ; the phenomenon, however, is certainly con- 
nected with atmospheric electricity ; and though we are not ac- 
quainted with all the circumstances which would enable us to com- 
prehend it, we must not reject a cause because it appears to us not 
to have an intensity proportional to the effects we would explain. 
— Ann. de Chim. xxix. 105. 

4. On the Existence of Iodine in a Mineral Substance. By 
M. Vauquelin. — The mineral in which M. Vauquelin has, for 
the first time, found this peculiar substance, was brought by 
M. Joseph Tabary from the neighbourhood of Mexico, and was 
labelled virgin silver in serpentine. It was of a whitish colour 
on its rubbed surface, presenting grains of metallic silver ; its 
fracture was lamellated, and of a yellowish green colour, witli 
some black portions and metallic silver. Twenty parts of the 
substance were acted upon by nitric acid with effervescence ; being 
boiled with it for some time, and then diluted, two insoluble 
portions appeared ; one very heavy, and falling instantly, whilst 
the other was light, and remained in suspension. When sepa- 
rated and washed, the first weighed 6A2 parts ; it fused easily by 
the blow-pipe, producing a purple flame, and ultimately a small 
globule of silver appeared in the centre of a fused mass like 
chloride of lead. The edges of the charcoal were covered with a 
yellow powder. The lighter matter was brown, and weighed 2.7 
parts ; it burnt, producing sulphurous acid, and leaving sulphuret 
of lead with a little iron=1.5S parts. 

A portion of the first matter, heated with muriatic acid; gave 
a red brown colour, and produced slight effervescence with the 
odour of chlorine. As the temperature rose the effervescence in- 


1 74 Miscellaneous Intelligence. 

creased, and a beautiful violet colour was developed, in conse- 
quence of which the vessel was removed from the fire. There re- 
mained at the bottom of the acid a yellow substance, containing" 
grey particles, which were dissolved by the hot water used for 
washing. This water had acquired a brown colour, and the 
power of colouring solution of starch of a fine blue. After many 
washings with water, alcohol was used, which in its turn became 
deeply coloured, and rendered a solution of starch of blue colour. 

In consequence of these appearances the muriatic solution was 
diluted and distilled, when violet vapour arose, and crystals of 
iodine condensed in the vessel. Though the yellow matter had 
boiled some moments with the muriatic acid, it still contained 
iodine, for 2.38 parts fused with two parts of potash, the residue 
dissolved in water, saturated with sulphuric acid, and mixed with 
starch, gave, with a few drops of chlorine, a fine blue colour ; 
1.63 grains of metallic silver were left. 

Five parts of the mineral were then mixed with two parts of 
caustic potash, and heated to redness for some time, after which 
treated with water 4.4,6 parts were left ; these acted upon by 
nitric acid dissolved without effervescence, leaving a yellow sub- 
stance resembling chloride of silver ; when dried it weighed 0.8, 
and was ascertained to be iodide of silver ; it gave 0.415 of 
silver to nitric acid. 

Hence it appears that as the potash had taken 0.5 parts from 
the five originally used, which were iodine, and that 0.8 of iodide 
of silver were formed, which would contain 0.425 iodine, the 
whole quantity of iodine was 0.925, which divided by 5=0.185, 
or 18.5 per cent, in the mineral. 

The alkaline solution before mentioned, saturated by nitric 
acid, became yellow ; and added to solution of starch, with a 
little chlorine rendered it blue. Nitrate of mercury precipitated 
it red. A portion of it neutralized by sulphuric acid evaporated 
to dryness, digested in alcohol, and the alcoholic solution eva- 
porated, gave quadrangular crystals of hydriodate of potash. 

Besides iodine and silver, the mineral contained sulphur, lead, 
and carbonate of lime. M. Vauquelin considers it as probable, 
that the sulphur is combined with the lead and silver, and the 
iodine with a part of the silver. In confirmation of this it is 
said, that when boiled with ammonia for some time, iodide of 
silver is separated from it. This, however, is against the generally- 
received opinion, that the iodide of silver is insoluble in ammo- 
nia.-— Ann. de Chim. xxxix. 99. 

5. Selenium in the Sulphur of the Lipari Islands. — Amongst the 
volcanic productions of the Lipari Islands is a sal-ammoniac, 
with sulphur in alternate white and brownish orange layers. The 
colour of the latter has generally been attributed to iron* but the 


Chemical Science, 175 

usual tests gave no indications of that metal ; arsenious acid, 
however, being detected. On dissolving the sal-ammoniac in water, 
a brownish residuum was left, which fused readily in a glass 
tube, and gave an orange-coloured sublimate. On hot coals it 
inflamed, evolving at first a mixed odour of sulphur and arsenic, 
and then the offensive smell of selenium. By digestion in nitric 
acid, till the orange colour disappeared, a solution was obtained, 
which, with sulphite of potash, threw down much of a cinnabar- 
coloured precipitate, possessing all the characters of selenium, 
whilst the solution evaporated gave acicular crystals of selenic acid. 
This discovery by M. Stromeyer of selenium amongst the vol- 
canic products of the Lipari Islands, renders it probable that the 
peculiar orange tint of the sulphur, found in those islands, proceeds 
chiefly from selenium, and not, as hitherto supposed, from arsenic 
combined with the sulphur. — Ann. Phil. N. S. x. 234. 

6. Natural Sources of Carbonic Acid Gas. — Bischoff and Nbg- 
gerath, in Schweigger's Journal, mention a pit on the side of 
the Lake of Laach, in which they found many dead animals, as 
birds of different kinds, squirrels, bats, frogs, toads, and also 
insects. On descending into the pit, and gradually sinking the 
head, they experienced the same sensation as when held over a 
vat in a state of fermentation. The quantity of gas evolved va- 
ries at different times. This evolution of carbonic acid gas is 
more striking in the volcanic Eifel. On the right bank of the 
river Kyll, nearly opposite to Birresborn, there is a spring 
named Brudelreis ; a provincial name for a boiling spring, and 
applied to this because it is perpetually agitated by large 
bubbles of gas, the agitation being so great as to produce a 
noise heard four hundred yards off. In its vicinity numerous 
dead birds are found, killed by the carbonic acid rising from the 
water ; and persons who kneel to drink at the spring are driven 
back by the gas. As MM. Bischoff and Nbggerath approached 
this spring, they heard the noise of its ebullition at a consider- 
able distance, and by approaching their faces to the surface of the 
turf in the vicinity of the spring, found that it was covered with a 
layer of carbonic acid gas. They did not observe any deleterious 
effects produced on the surrounding trees or grass. On emptying 
the basin no more water was collected, shewing that it was rain, 
not spring water ; but the gas continued to rise through the fis- 
sures of the rock in some places, with such force as to feel to the 
hand like wind from a bellows. Lime-water poured into one of 
the fissures became turbid, and caused the appearance of ebulli- 
tion again, but it was not ascertained whether the gas was pure 
carbonic acid or not. — Edin. Phil. Jour. xiii. 191. 

7. Process for the Detection of Phosphate of Lime.— A process 


176 Miscellaneous Intelligence. 

is given, as one recommended by MM. Vauquelin and Thenard, 
for the detection of phosphate of lime, founded upon its conversion 
by potassium into a phosphuret, and the production of phosphuret- 
ted hydrogen, either with water or acids, by the latter body. The 
gas is recognised by its well-known odour, and indicates the pre- 
sence of a phosphate in the matter originally used. The decompo- 
sition is to be effected in a glass tube, 3 or 4 millimetres (0.15 inch) 
in diameter, and about 4 centimetres (1.5 inches) long ; a centi- 
gramme (0.15 grain) of potassium is to be placed at the bottom, and 
the substance supposed to contain the phosphate in powder is to 
be pressed down upon it. The tube is then to be gradually heated, 
the potassium sublimed through the substance, and, when cold, 
the excess of potassium removed by the introduction of mercury. 
The matter remaining, when exposed to a moist air, or when 
touched by muriatic acid, will evolve the odour of phosphuretted 
hydrogen, if any phosphate were present ; or a little diluted acid 
may be introduced into the tube, and the gas evolved obtained. 
Of course, any sulphate which may be present must be removed, or 
the odour of sulphuretted hydrogen would seriously interfere with 
the delicacy of the test. — Jour, de Chim. Med. Jan. 1825. 

8. Metallic Titanium in Iron Furnaces. — Cubic crystals of me- 
tallic titanium, similar to those discovered by Dr. Wollaston in 
the iron-furnaces of South Wales, have also been found by Dr. 
Walchner, of Friburg, in the Breisgau, in the founderies of the 
highlands of Baden. The piece of slag examined was from the 
high furnace of Kandern, in which pea-iron ore only is smelted. 
Being desirous of ascertaining the presence of the titanium in the 
pea-iron ore, an attempt was made with the blow-pipe, and its 
presence, Dr. Walchner says, indicated, though in very small 
quantity. — Phil. Mag. lxvi. 124. 

9. Rose on the Separation of Titanic Acid from Oxide of Iron. — 
The difficulty of separating titanic acid from oxide of iron, is well 
known to chemists, no process but what is very imperfect being 
as yet known. M. Rose, who has had frequent occasion to com- 
bat this difficulty, has discovered and published a method which 
not only renders analytical processes more perfect, but very much 
facilitates the preparation of titanic acid from its more abundant 
natural compounds. 

A solution of titanic acid and oxide of iron being obtained in 
muriatic acid, if tartaric acid be added to it, and the whole be 
diluted with water, then a great excess of caustic ammonia may 
be added without the smallest precipitate of titanic acid or oxide 
of iron being produced. If to this solution hydrosulphuret of am- 
monia be added, it exerts no action on the titanic acid, but changes 
all the oxide of iron into sulphuret, which separates perfectly. 


Chemical Science. 177 

This precipitate is to be carefully washed with water, containing 
a few drops of hydrosulphuret of ammonia, until all the tartrate 
is removed ; it is then to be dissolved in muriatic acid, heated 
to drive off the sulphuretted hydrogen, treated with nitric acid to 
peroxidize the iron, and then precipitated by ammonia : in this 
way the iron is procured. The titanic acid may be separated from 
the solution, (if it contains no fixed parts,) by evaporating to dry- 
ness, and heating red hot in contact with air, until all that is vo- 
latile is dissipated, and the charcoal is burnt off. This is best 
done in a small platina crucible in a muffle ; titanic acid remains. 
This method appears to be equally advantageous for the prepa- 
ration of titanic acid from minerals containing it, combined with 
protoxide of iron, and which may be dissolved in strong muriatic 
acid, after having been pulverized. As there is then no occasion 
carefully to wash the sulphuret of iron, that labour is saved, and 
the process becomes as short, or shorter, than any other known. — 
Ann. de Chim.xxix. 130. 

10. Wohler on Tungsten, and its Combinations. — M. Wohler 
prepares his tungsten by fusing together pulverized wolfram and 
carbonate of potash ; the tungstate of potash is dissolved out by 
water, muriate of ammonia is added, the whole is evaporated to 
dryness, and heated red hot in a Hessian crucible. The mass dis- 
solved in hot water leaves a heavy black powder, being the oxide 
of tungsten. It should be boiled in weak solution of potash, and 
washed in hot water. It is readily converted into tungstic acid by 
heating it in an open crucible ; it takes fire, and burns vividly 
into a yellow powder. 

Oxide of Tungsten. — Tungstic acid, heated in hydrogen gas, as 
Berzelius has shewn, becomes first blue, then of a deep brown co- 
lour ; the substance produced has a lustre almost metallic, and 
when polished takes the colour of copper. Tungstic acid, in con- 
tact with zinc in dilute muriatic acid, also becomes blue, and ul- 
timately forms films of a fine copper-colour. In this state the sub- 
stance exists as an oxide, and must be retained under water ; if 
exposed to air it becomes blue again, and ultimately yellow tung- 
stic acid. The black powder obtained above appears almost as; 
the metal, when compared with this substance, and when rubbed 
with a polisher, takes a white metallic lustre. It is> however, 
only oxide of tungsten, as is shewn by the increase of weight 
when burnt ; it inflames in the air much beneath a red heat, and 
100 parts absorb 8 parts of oxygen in becoming tungstic acid, 
the same quantity as is absorbed by the brown oxide ; whilst me- 
tallic tungsten requires, for every 100 parts, the addition of 2£ 
parts of oxygen to become tungstic acid. 

A singular and, as yet, inexplicable phenomenon, occurs in the> 
preparation of oxide of tungsten from tungstic acid, by hydrogen,. 

Vol. XX. N 


178 Miscellaneous Intelligence. 

The preparation of a pure tungstic acid, when it has once contain- 
ed a fixed alkali, is known to be difficult. When an acid con- 
taining a little potash or soda is used for the preparation of the 
brown oxide by hydrogen, this oxide is never obtained, but always 
metallic tungsten, and in this way the metal may be readily pro- 
cured. It should be washed with pure potash, to dissolve the 
difficultly soluble tungstate with which it is mixed. Tungsten 
then appears as a white metallic powder, very heavy, which, 
heated in the air, takes fire, 100 parts absorbing 25 parts of oxy- 
gen to become tungstic acid. 

Oxide of Tungsten and Soda. — Neutral tungstate of soda, heated 
in hydrogen, suffers no change ; but acid tungstate of soda so 
treated soon acquires on the surface the colour and lustre of cop- 
per, which ultimately propagates through the mass. On cooling, 
the colour becomes gold yellow, and then water added dissolves 
neutral tungstate of soda, and leaves a heavy crystalline powder, 
of the colour and almost the lustre of gold. To purify the powder 
it should be first boiled in water, then in concentrated muriatic 
acid, then in solution of pure potash, and ultimately again in water. 
The acid tungstate of soda is prepared by adding tungstic acid to 
the neutral salt in a state of fusion, until no more is dissolved. 

This metallic-looking substance is a compound of oxide of tung- 
sten and soda. It is crystallized in regular cubes, which are 
larger as the operation has been more slowly conducted. Cavities 
frequently occur in the reduced saline mass, lined with very bril- 
liant small cubes. It has a perfect metallic lustre, even when 
rubbed on paper ; its colour is very like that of gold, and, when 
suspended, as in fine powder in water, and seen before the sun, like 
gold it is transparent, and of a green colour. No acid, or mix- 
ture of acid, except concentrated fluoric acid, will affect it, nor 
do solutions of pure alkalis change it. Heated in the air, it 
changes colour, softens, appears to fuse, and forms a transparent 
mass, which, on cooling, becomes a white enamel, soluble in wa- 
ter, and from which an acid precipitates tungstic acid. The de- 
composition, however, is never perfect throughout, even in oxygen 
gas, though combustion then occurs. In a vacuum the compound 
endures heat without any change. The fusible substance appears 
to be a tungstate of soda, but it seemed difficult to decide whether 
the elements of the compound were in the state of metals or 
oxides. 

It was found that, at a high temperature, the substance was 
affected by chlorine ; highly heated in that gas, a chloride of 
tungsten volatilized, and a green mass remained, which, with 
water, gave chloride of sodium and a green powder, the latter a 
mixture of a little oxide of tungsten with tungstic acid ; the tung- 
stic acid was in greater quantity than the oxide and chloride to- 
gether. Hence the compound contained oxygen, which at first 


Chemical Science. 179 

appears to have been distributed 60 as to form oxide of tungsten 
and soda, and, after the action of the chlorine, to have combined, 
forming tungstic acid ; 873 parts of the compound, decomposed 
by chlorine, gave 157 chloride of sodium = 89 soda; conse- 
quently, 10.6 of soda per cent, in the compound. 

Sulphur heated with this body decomposed it entirely,' convert- 
ing the tungsten into sulphuret. This was transformed by nitro- 
muriatic acid into tungstic acid* 45 parts being obtained from 48.7 
of the compound. These correspond to 86.2 per cent, of oxide of 
tungsten in the compound* the residue t= 13.8 being, of course, 
soda. Hence the compound contains, 

Calcul. 

Oxide of tungsten 4 atoms 87.81 - 86.2 
Soda 1 „ 12.19 - 13.8 

100.00 100.0 

Attempts were made to produce this compound by directly com- 
bining oxide of tungsten with soda ; when heated together me- 
tallic tungsten and tungstate of soda were produced. When acid 
tungstate of potash was heated in hydrogen, pure metallic tung- 
sten was obtained. 

Chloride of Tungsten. — Sir H. Davy first formed chloride of 
tungsten. M. Woliler shews the existence of three of these com- 
pounds. When black oxide of tungsten is heated in chlorine in a 
tube, combustion takes place, dense fumes are formed, which 
ultimately produce a thick sublimate of white scales, resembling 
in appearance native boracic acid; this is the perchloride of tung- 
sten. In the air it gradually becomes tungstic and muriatic acids i 
the change is more rapid in water. It is volatile at a low tempe* 
rature, without fusing previously. Heated on platina foil, it is also 
decomposed into muriatic and tungstic acid. As water converts 
it thus into muriatic and tungstic acids, it must consist of, 

Chlorine 3 atoms - 35.9 

Tungsten 1 „ - 64.1 

100.0 
166 grains of this compound dissolved in ammonia, evaporated and 
heated, gave 130 grains of tungstic acid =; 62.65 of tungsten for 
100 of chloride. 

When metallic tungsten is heated in chlorine, it takes fire and 
burns into a chloride, with a minimum of chlorine. The com- 
pound appears sometimes as delicate fine needles, of a deep-red 
colour resembling wool, but more frequently as a fused deep-red 
compact mass, with the brilliant fracture of cinnabar. When 
heated, it fuses, boils, and yields a red vapour. In water it gra- 
dually decomposes, producing muriatic acid and oxide of tungsten. 
This compound dissolves in solution of pure potash, evolving hy- 
drogen, forming chloride of potassium, and tungstate of potash. 

N 2 


180 Miscellaneous Intelligence, 

Similar effects take place in ammonia. The chloride appears 
analogous to the oxide, and should be composed of 

Chlorine 2 atoms 26.79 

Tungsten 1 „ 73.21 


100.00 

The third compound, on the composition of which no experiment 
has been made, is generally formed at the same time with the 
maximum chloride, though in small quantity. It was once pro- 
duced in larger quantity, by heating the sulphuret of tungsten in 
chlorine. This is the most beautiful compound of all, existing in 
long transparent crystals, of a fine red colour ; it readily fuses, 
and on cooling crystallizes in long needles on the glass. It is 
more volatile than the others ; it instantly changes in contact 
with the air into tungstic acid. Thrown into water it swells like 
caustic lime, disengages heat, a slight noise is heard, and it is 
instantly changed into tungstic acid. — Ann. de Chim. xxix. 43. 

11. Composition of Ancient Glass. — A fragment of ancient Ro- 
man glass found near Brool, has been analyzed by Dr. Rudolph 
Brandes, and found to contain silica, soda, oxide of lead, oxide of 
manganese, oxide of iron, lime, and alumina. The silica formed 
about two-thirds of the mass. The glass had been so far affected 
by water and other agents acting upon it for a great length of 
time, as to have lost its transparency, except towards the centre. 
It had a milky white colour, with a bluish cast, and in some parts 
a lustre very similar to that of gold. This resulted from the thin 
plates into which the glass had disintegrated, and which caused it 
when broken, pressed, or scraped, to fall into small leaves like 
mica. 

12. Action of Lime upon Alcohol. — The following experiment is 
one made by Dr. Menici, and described in the Giornale di Fisica, 
viii. 50. Two portions of alcohol, of three ounces each, the one 
being at 35° B. (s. g. 842,) and the other at 28° B. (s. g. 880,) 
were put into separate bottles, and to each was added three denari 
(about 3.5 dwts.) of caustic lime. The bottles were closed up and 
left for four months. At the end of that time the liquor in the 
second bottle had assumed a yellow colour, which, in two months 
more, deepened to a red. Being then opened, it was found to 
have a peculiar aromatic odour ; by distillation unchanged al- 
cohol came over from the clear solution, and a residue was left, 
which, when dry, weighed about a denaro, and resembled a red 
resin ; it softened by heat, and burnt with a bright flame and 
much smoke. The stronger alcohol, on the contrary, had ac- 
quired no tint like that of the portion just described, but slowly 
took a light bluish tint. Hence it appears that, in contradiction 


Chemical Science. 181 

to the received notion, diluted alcohol is more readily acted upon 
and changed by lime than that which, by concentration, has been 
deprived of a part or the whole of its water. 

13. Melaina, or die Black Principle of Sepia. — M. Bizio, during 
a chemical investigation of the ink of Sepia, has found reason to 
distinguish the black substance contained in it from all other sub- 
stances, in consequence of its properties, and has called it Melaina. 
It may be obtained in a pure state, he says, by heating the black 
substance of sepia in a water-bath, with a mixture of 1 part nitric 
acid and 1 1 of water, until the liquor becomes of a yellow colour ; 
it is then to be removed, to have much distilled water added to it, 
and to be filtered ; is then to be boiled repeatedly in distilled 
water, washed in an alkaline, subcarbonate, then again washed 
with cold water, and will thus be obtained pure. 

This substance is perfectly black, insipid, inodorous, heavier 
than water, unchanged in the air. It does not affect test papers ; 
it is insoluble in cold water, but dissolves in hot water, forming a 
very black solution. Alcohol and ether do not dissolve it. The 
aqueous solution is perfectly precipitated by sulphuric, nitric, or 
muriatic acid, but oxalic, citric, and acetic acids do not produce 
this effect; neither does alcohol or bi-chloride of mercury render 
the solution turbid. Cold sulphuric acid dissolves it, heat applied 
causes decomposition, and sulphurous acid is produced. Cold 
nitric acid acts upon it, liberating pure nitrogen ; heat applied 
invigorates the action, evolving nitric, oxide, &c. ; muriatic acid, 
either cold or hot, scarcely acts upon it. The caustic alkalies 
dissolve the substance readily, especially when heat is applied, 
and a viscid black solution is produced ; acids precipitate it again, 
leaving a clear solution. When introduced into a flame, it burns 
suddenly. On a hot iron it separates, as if gaseous or vaporous 
matter was passing off, and when heated in close vessels, yields 
unequivocal indications of the presence of nitrogen. — Giornale de 
Fisica, viii. 105. 

14. Analysis of the Solanum Pseudo-Quina.—M. Vauquelin has 
produced an elaborate analysis of the bark of the solanum pseudo- 
quina, and finds it to contain a bitter principle, purely vegetable, 
to which it owes its virtues, and amounting to 8 per cent., a resin- 
ous matter, about 2 per cent. ; a small quantity of viscid fatty 
matter ; a very abundant animal substance, which, in consequence 
of being combined with sub-malates of potash and lime, presents 
alkaline characters; starch, in minute quantity ; oxalate of lime, 
5 or 6 per cent. ; malates of lime and of potash ; carbonate of lime, 
5 per cent. ; oxide of manganese, in notable quantity, united to 
malic and oxalic acids ; malate of iron, a minute portion of mag- 
iwiWdn an atom of phosphate of lime, and ligneous matter, amount- 
ing to two-thirds of the whole weight. 


182 Miscellaneous Intelligence. 

The animal matter, when heated, gave carbonate of ammonia, 
empyreumatic oil, and charcoal. It appears to form a true com- 
bination with potash or lime, or their subsalts, and seems, in part, 
to neutralize the alkali, whilst, at the same time the alkali confers 
great solubility on the substance. M. Vauquelin expresses his 
fear that the supposed vegeto- alkaline bodies, which have been 
procured from many plants of the solanum species, and received 
names as new substances, are only combinations of organic matter 
with alkalies, or their subsalts. — Mem. duMus, xii. 204, 


III. Natural History. 

1. Meteoric Appearance on Ben" Lomond ; Ascent of Vapour. — The 
following appearance is ^escribed by Mr. W. T. Ains worth, who, 
with Mr. Savage, observed it on Sunday, May 8, from the summit 
of Ben- Lomond. At three o'clock in the morning a cold damp 
wind blew from the south-west, the sky there being covered with 
dark dense clouds, whilst, towards the east, a small extent of deep 
azure sky was seen, where, however, clouds were fast forming. In 
a short time it began to rain, and continued to do so incessantly 
for two hours, when, in an interval of fine weather, the travellers 
again resumed the ascent of the mountain. The clouds then broke, 
and the sun shone forth ; and about this time, says Mr. Ainsworth, 
" having our faces turned towards the west, we observed streams 
of vapour rise from the earth in two or three places (at about a 
mile distance from us, and 400 or 500 yards apart from one ano- 
ther,) and ascend in a perfectly straight direction towards a heavy 
dark nimbus, passing over at the time. Using my hat as a 
level, I lay down on the ground, and found it to be rather lower 
than the situation I occupied near the summit of the mountain. 
Their bases were, I should suppose, not above three or four feet in 
diameter, which did not increase nor diminish till their junction 
with the cloud, when they assumed a more conical shape, the base 
of which was in the cloud. They resembled immense columns, or 
pillars ; they had no motion forwards or backwards, and, as far as 
our eye could ascertain, they had no revolving motion upon their 
own axis. The attraction existing between the pillar and the 
cloud was so great, that, at the supervention of a strong breeze, 
though the centre of the pillar yielded, it never deviated from its 
columnar form, and the top remained precisely over the point 
from which it arose, forming, as it were, for the time, a segment 
of a circle. A short time after perceiving this remarkable phe- 
nomenon, we had occasion to remark the same process taking 
place on the lake itself. The columns, though at a great distance 
'from us, we could plainly perceive were vapour, and not water, 
"but they did not take on themselves so uniform an appearance. 
During this interesting scene, I hung two small balls hewn out of 


Natural History. 183 

the pith of an elder tree at the end of a stick of gum lac, a strong 
insulating substance, and more portable than glass ; the repulsion 
from one another was such as to indicate that the atmosphere was 
in a high state of electricity. Hygrometer I had none. Thermo- 
meter stood at 45°. — Edin. Phil. Journal, 185. 

2. Description of an Earthquake. — The following minute ac- 
count of an earthquake is given by Professor Ferrara, of Catania, 
who seems to have been in the most favourable situation for the 
observation of such a phenomenon. On Wednesday, the fifth of 
March, 1823, at twenty-six minutes after five P. M., Sicily suffered 
a violent shock of an earthquake. I was standing in the large 
plain before the palace, in a situation where I was enabled to pre- 
serve that tranquillity of mind necessary for observation. The 
first shock was indistinct, but tending from below upwards ; the 
second was undulatory, but more vigorous, as though a new im- 
pulse had been added to the first, doubling its force ; the third was 
less strong, but of the same nature ; a new exertion of the force 
rendered the fourth equal, on the whole, to the second ; the fifth, 
like the first, had an evident tendency upwards. Their duration 
was between sixteen and seventeen seconds ; the time was pre- 
cisely marked by the second's hand of a watch which I had with 
me. The direction was from north-east to south-west. Many 
persons who ran towards me from the south-west at the time of 
this terrible phenomenon, were opposed by the resistance of the 
earth. The spear of the vane on the top of the new gate connected 
with the palace, and upon which I fixed my eyes, bowed in that 
direction, and remained so until the Sabbath, when it fell ; it was 
inclined to the south-west in an angle of twenty degrees. The 
waters in the great basin of the botanical garden, as was told me 
by an eye-witness, were urged up in the same direction by the 
second shock ; and a palm-tree, thirty feet high, in the same gar- 
den, was seen to bow its long leafless branches alternately to the 
north-east and south-west, almost to the ground. The clocks in 
the observatory which vibrated from north to south, and from east 
to west, were stopped, because the direction of the shock cut 
obliquely the plane of their respective vibrations, and the weight 
of one of them broke its crystal. But two small clocks in my 
chamber kept their motion, as their vibrations were in the direction 
of the shock. The mercury in the sismometer preserved in the 
observatory was put into violent motion, and at the fifth shock it 
seemed as much agitated as if it were boiling. — Silliman's Journal, 
ix. 216. 

3. Eodraordinary Rise of the Rio de la Plata. — This river, as is 
well known, is flooded at certain periods ; and, like the Nile, in- 
undates and fertilizes the country. The Indians then leave their 


184 Miscellaneous Intelligence. 

huts and betake themselves to their canoes, in which they float 
about until the waters have retired. In April, 1793, it happened 
that a violent wind heaped up the immense mass of waters of this 
river to a distance of ten leagues, so that the whole country was 
submersed ; and the bed of the river remained dry in such a man- 
ner, that it might be walked over with dry feet. The vessels 
which had foundered and sunk were all exposed again ; and there 
was found, among others, an English vessel, which had perished in 
1762. Many people descended into this bed, visited and spoiled 
the vessels thus laid dry, and returned with their pockets filled 
with silver, and other precious articles, which had been buried 
more than thirty years in the deep. This phenomenon lasted 
three days, at the expiration of which the wind abated, and the 
waters returned with fury into their natural bed. — Edin. Phil. 
Journal, xiii. 188. 

4. Fall of a Meteoric Stone at Nantgemory, Maryland, Feb. 10, 
1825. By Dr. Carver. — I take the liberty of forwarding you a 
notice of a meteoric stone, which fell in this town on the morning 
of Thursday, Feb. 10, 1825. The sky was rather hazy, and the 
wind south-west. At about noon the people of the town, and of 
the adjacent country, were alarmed, by an explosion of some body 
in the air, which was succeeded by a loud whizzing noise like that 
of air rushing through a small aperture, passing rapidly in a 
course from N.W. to S.E., nearly parallel with the river Potomac. 
Shortly after a spot of ground on the plantation of Captain W. 
D. Harrison, Surveyor, of this port, was found to have been re- 
cently broken, and on examination a rough stone, of an oblong 
shape, weighing 16lbs. 7oz. was found about eighteen inches 
under the surface. The stone when taken from the ground, about 
half an hour after it is supposed to have fallen, was sensibly 
warm, and had a strong sulphureous smell. It has a hard vitreous 
surface, and when broken appears composed of an earthy or sili- 
ceous matrix, of a light slate colour, containing numerous globules 
of various sizes, very hard and of a brown colour, together with 
small portions of brownish yellow pyrites, which become dark- 
coloured on being reduced to powder. I have procured for you a 
fragment of the stone, weighing 4lbs. 10oz., which was all I could 
obtain. Various notions were entertained by the people in the 
neighbourhood on finding the stone. Some supposed it propelled 
from a quarry eight or ten miles distant on the opposite side of 
the river, while others thought it thrown by a mortar from a 
packet lying at anchor in the river, and even prepared manning 
boats to take vengeance on the captain and crew of the vessel. 

I have conversed with many persons living over an extent of 
perhaps fifty miles square ; some heard the explosion, whilst 
others heard only the subsequent noise in the air. All agree in 


Natural History. 185 

stating that the noise appeared directly over their heads. One 
gentleman, being about twenty-five miles from the place where 
the stone fell, says that it caused his whole plantation to shake, 
which many supposed to be the effect of an earthquake. I cannot 
learn that any fire-ball or any light was seen in the heavens. 
All are confident that there was but one report, and no peculiar 
smell in the air was noticed. 

Captain Harrison, whose account is added to this, and on whose 
grounds the stone fell, states, from his own observation, that the 
time was between twelve and one o'clock, that the explosion was 
sharper than a cannon ; that then a buzzing noise was heard over 
head, first like that of a bee, but increasing till like a spinning 
wheel, or a chimney on fire, and that then something was heard to 
fall, the time from the explosion to the fall being perhaps fifteen 
seconds. After a while the stone was found about twenty-two or 
twenty-four inches beneath the surface ; it had a strong sul- 
phureous smell, and there were black streaks in the clay, which 
appeared marked by its descent ; the mud was thrown in different 
directions from thirteen to sixteen steps. The stone, when 
washed, weighed lGlbs. It fell within 250 yards of Captain Har- 
rison's house, and within a hundred yards of the habitation of the 
negroes. This account was given from memory on the 28th of the 
following April. — Silliman's Journal, ix. 351. 

5. Composition of Aerolites. — M. G. Rose, of Berlin, has suc- 
ceeded in separating crystals of pyroxene from a large specimen of 
the aerolite of Juvenas, and has measured the angles with the re- 
flective goniometer : one of the crystals is of the octoedral variety, 
represented in the 109th figure of Haiiy's mineralogy. The same 
rocky tissue contains microscopic hemitrope crystals, which ap- 
pear to be felspar, with a base of soda, i. e., albite. 

M. Rose has also examined, at the request of M. Humboldt, the 
aerolite of Pallas, and the trachytes collected on Chimborazo, and 
the other volcanoes of the Andes : he has found that the olivine 
of the mass of Pallas is perfectly crystallized, and that the trachytes 
of the Andes are, in part, mixtures of pyroxene and albite like the 
aerolite of Juvenas. Perhaps the same is the case with those of 
Jonzac and Stannern, of which, as yet, the masses have not been 
studied mineralogically by trituration, the microscope, and the 
reflective goniometer. — Ann. de Chimie, xxix. 109. 

6. Flexible Marble of Berkshire Country, U.S. — Dr. Dewey states 
that this marble, which has been known for some years, and until 
lately was found chiefly in West Stockbridge and Lanesborough, 
is now obtained at New Ashford, from an extensively wrought 
quarry. He had three fine specimens of it in slabs from five to 
six feet in length, and seven inches in width. Its flexibility and 


186 Miscellaneous Intelligence. 

elasticity may be shewn as it stands upon one end, by applying a 
moderate force to the middle or the other end. Its flexibility is 
seen, too, by supporting the ends of it in a horizontal position upon 
blocks. The marble has various colours, nearly white, with a 
reddish tinge, gray, and dove-coloured. Some of it has a fine 
grain ; other specimens are coarsely granular, and have a loose 
texture. It is not uncommon for one side of a large block to be 
flexible, while the other part is destitute of this property. It takes 
a good polish, and appears to be carbonate of lime, and not a mag- 
nesian carbonate. 

It is well known that Dolomieu attributed the flexibility of the 
marble he examined to exsiccation, and that Bellevue ascertained 
that unelastic marble might be made elastic by exsiccation. The 
flexible marble of this counry, however, loses this property in 
part on becoming dry. When it is made thoroughly wet by the 
operation of sawing, or of polishing, it must be handled with 
great care, to prevent its breaking ; and the large slabs of it can- 
not be raised with safety unless supported in the middle as well as 
at the ends — Silliman's Journal, ix. .241. 

7. Extraordinary Minerals discovered at Warwick, Orange 
County, N. Y. — These extraordinary minerals are described by 
Dr. Fowler, in Silliman's Journal, ix. p. 242. They belong, he 
says, to the formation of crystalline limestone, which there, per- 
haps, has no parallel in any other region of the world, and were 
discovered in the township of Warwick. " What will be thought 
of spinelle pleonaste, the side of one of whose bases measures three 
to four inches, or twelve to sixteen inches in circumference ? 
These crystals are black and brilliant, sometimes aggregated, at 
other times solitary ; at this locality seldom or ever less than the 
size of a bullet. Some are partly alluvial, their matrix decompos- 
ing, but when unaltered, they are found associated with what has 
never yet been described, namely, crystals of serpentine, slightly 
rhomboidal prisms, of a magnitude parallel with the crystals of 
spinelle, often greenish and compact, at other times tinged yellow 
by an admixture of Brucite." 

" In the same mass also are associated very large prismatic 
crystals of chromate of iron, at least so they appear to be, by the 
beautiful green colour which they impart to nitrate of potash, hav- 
ing a specific gravity of 4.3. Some of these prisms are an inch in 
breadth, and two inches in length, with two lateral faces broader 
than the rest." 

" Not far from the same locality also is found, associated gene- 
rally with a fine green and crystalline serpentine, the red spinelle, 
of various shades and degrees of translucence," $*c. " These are 
from a line in diameter to three quarters of an inch on each side 
of the bases ; now and then they occur in hemitrope." " At By- 


Natural History. 187 

ram, also, a few miles from Sparta, the red spinelle has been found 
by William Inglis, Esq. Some of these approaching to a choco- 
late brown in colour, give a base of one inch and a quarter on 
each plane." 

M The magnitude of other crystals at this place (Warwick) 
is equally surprising as that of the spinelles. Crystals of scapolite 
terminated, are to be found each of the six faces of the prism, 
measuring four inches, or a circumference of twenty-four inches, 
or even more. They are, of course, rough and corroded ; but the 
smaller prisms, often with narrow replacements on the edges, are 
very perfect, and almost transparent : all of these slightly tinged 
with green." 

" Of the amphibole genus we meet with several varieties, finely 
crystallized ; the black with six-sided prisms, each face sometimes 
is an inch in breadth ; actynolite in short and confused prisms, 
and a chocolate brown finely-crystallized variety, both in large and 
crystals of the usual form, and also of an extraordinary form, hav- 
ing the obtuse angle sometimes replaced by a broad face." 

*' Crystals of augite abound here of gigantic magnitudes, and 
sometimes when smaller, of considerable perfection of form; they 
are generally greyish green." 

" In a very singular bed, subordinate to, and, indeed, in the 
crystalline limestone, occurring in the form of a breccia of the old 
red sandstone, red graphic granite, and white felspar, I have found 
partly diaphanous, softish, green octoedral crystals of considerable 
magnitude, for which I know of no ascertained character. They 
appear almost similar in substance to steatite, being easily cut by 
a knife. Tiiey are not, however, found as the spinelle of this 
locality in carbonate of lime. Considering, therefore, this mineral 
as new, I propose to call it pseudolite, in allusion to its affinity to 
the pseudamorphous crystals of steatite." 

8. Globules of Water in Amethyst. — Mr. Webb, of Providence, 
U. S., has had occasion to observe that globules of water and air 
were by no means unfrequent in specimens of amethyst, which 
came under his eye. Many of them were highly interesting from 
the size of the globule or portion of liquid, the form of the cavity 
containing it, the exhibition of double refraction through the 
crystal which it afforded, §c. He remarks that most of these 
specimens were found among such as had been rejected on account 
of being too pale for good cabinet specimens, and thinks it proba- 
ble that good specimens are continually neglected for want of 
sufficient and close examination. — Silliman's Journal, ix. 246. 

9. Recent Formation of Brown Hematitic Iron Ore. — On ex- 
amining a set of cast-iron pipes, which had lain for some years in 
the line of one of the streets in the New Town of Edinburgh, 


188 Miscellaneous Intelligence. 

we were surprised to find the sand in which they had been laid, 
where in contact with the pipes, very compact and brown in co- 
lour. On breaking some of the masses, we found the connecting 
matter to be brown iron ore, and in cavities of the compacted 
sand this brown iron ore, exhibiting that particular lustre ap- 
proaching to adamantine, and the reniform shape with the granu- 
lated surface of brown hematite. Here, then, we have an instance 
of the formation, by the action of percolating water on the iron 
of the pipes, of an ore of iron which some observers arrange with 
the igneous mineral formations. — Edinburgh Philosophical Journal, 
xiii. 193. 

10. On the Habits of Beavers. By M. Geoffroy St. Hilaire. — 
A beaver has lived in the menagerie of the king's garden for 
some years ; it is one of those from the Rhone, which live sepa- 
rately like water-rats. This animal was defended from the cold 
of winter only by a more abundant litter. It happened one night 
that the cold had increased ; the shutters of the hut closed but 
badly, and the beaver was urged to find means of preserving itself 
from the effects of a very rigorous temperature. It had been 
the custom to give it a certain number of fresh branches to sa- 
tisfy its desire of gnawing, and occupy it during the night, these 
were found stripped of the bark in the morning ; food also was 
given it, consisting of greens and fruits, of an evening, before 
shutting it up, by closing the shutter, which was made like a pent- 
house. It had snowed too, and the snow had collected in one cor- 
ner of its hut. 

Such were the materials which the beaver, in this instance, 
possessed to form a wall of defence against the external air and 
cold ; the branches were interwoven between the bars of the hut, 
exactly in the way that basket-makers interweave the small 
osiers round the principal stems, going from one to the other by 
contrary turns. Thus arranged, they left intervals, in which the 
beaver placed the carrots, potatoes, and litter which remained, 
each substance being cut so as to occupy and fill the spaces left. 
Finally, as if the animal knew that the whole should be co- 
vered with a compact cement, he employed the snow to fill 
even the smallest aperture which remained. The wall filled 
up two-thirds of the gap, and every thing which had been given 
to the animal, even the whole of its food, was employed in the 
construction. 

In the morning, the snow having frozen between the branches 
and the shutter, the latter adhered to the new wall; when, how- 
ever, removed, the work of the beaver became exposed. The boy, 
who attended to the animal, was so surprised at this unexpected 
production, that he came and informed me of it before any thing 
was deranged. — Mem. de Mus. xii. 232. 


Natural History. 189 

11. Tenacity of Life in Laroa. — Dr. Yule states, that "the 
larva of a carnivorous beetle, sent to me from Inverary, not 
merely lived, but moved briskly in strong alcohol, the day after 
it was enclosed in a phial, filled with that liquor. Bonnet found 
that the larva of papilio brassicae, frozen under a temperature 
of 14° Fahr., revived perfectly on being thawed. — Edin. Phil. 

Jour. xiii. 73. 

• 

12. Argonauta Argo. Naples. — Academy of Science, Dec. 14. 
1824. — The Chevalier Pole read two memoires on the argonauta 
argo of Linnaeus, caught on the coast of Pausillipo, near Naples, 
which he had the opportunity of examining whilst alive. He de- 
scribed the organization and parts of the animal, and has deter- 
mined the most curious points of its generation. He has been 
able to remark, by means of the microscope, that the shell of this 
insect exists with the animal whilst yet in the egg ; and what is 
still more extraordinary is, that the animal is not naturally at- 
tached to the shell. Conjectures are ventured upon the manner in 
which the shell is developed.—/?^. Ency. xxvi. 912. 

13. Recent Vegetation of Ancient Beans. — " As I happened to be 
at Naples, when first Herculaneum was discovered, 1 should have 
told you that some leathern bags of beans, answering exactly to 
our kidney ones, were found in several corners of their window- 
seats. The Romans were very fond of that kind of supper, as 
appears by a line of Horace : 

' Oh quando faba Pythagoras, &c' 
Some English gentlemen were curious enough to sow them on 
their return ; and notwithstanding their having been, to appear- 
ance, dead for so many centuries, yet did they grow and pro- 
duce. Dr. Laws on tried the experiment in a small garden of 
his at Chelsea, and it succeeded." — Monthly Mag. lx. 98. 

14. On tlie Origin of Ergot. By General Martin Field.— Ge- 
neral Field states, that his intention is not to support or oppose 
any theory of the org in and nature of ergot, but simply to repeat 
the facts as he observed them. The field of rye examined was 
within fifty yards of the house, (New Fane, Vermont,) and of that 
kind known in the neighbourhood as the Norway, or White, 
Rye, which has been observed to be more productive of ergot 
than the English spring rye, or that said to be from the Isle of 
Candia. Ergot has been very abundant in this vicinity during 
the last season. 

" The field of rye, which I very frequently examined, was in 
full blossom about the 3oth of June, 1824, but I discovered no 
appearances of ergot till the 22d of July. From that time until 
the 12th of August, when the rye was harvested, it might be 


190 * Miscellaneous Intelligence. 

found of various dimensions. Upon minute examination 1 disco- 
vered that every grain of ergot, as it emerged from the glume, 
had attached to its apex the shrivelled rind of a grain of rye, which 
had the appearance of once being in a healthy state. This led 
me to conjecture, that a diseased state of the rye was the primary 
cause of the ergot. To ascertain the fact I repaired to the rye- 
field, where I discovered groups of flies collected upon the 
heads of rye, apparently in the pursuit of something within the 
glume. On opening the valve of the glume where the flies were 
thus collected, I found the saccharine juice of the grains of rye 
was oozing out, and would soon produce drops. I was then con- 
vinced that it was this saccharine fluid which was so inviting to 
the multitude of flies that collected upon those heads of rye 
which contained any diseased grains. Having collected a num- 
ber of grains of full-grown size, and exhibiting appearances 
similar to those above described. I placed the same under a mi- 
croscope, by which I could clearly discover a small orifice in 
each, near the end opposite to that to which the thread of nu- 
trition had been attached. I could also discover, that the juice of 
the grain was still discharging from the orifice. 

On the morning of the 1st of August, by observing the groups 
of flies, I found two heads of rye near each other, each of which 
contained a grain of punctured or diseased rye. The culms I 
tied to a stake drove between them, the better to enable me 
again to find them, and to observe their future appearances. At 
that time the punctured grains exhibited no symptoms of decay, 
otherwise than a small discharge of fluid. During the first day 
the flies were busily employed in extracting their delicious beve- 
rage from the orifice of each grain, and when it did not flow in 
sufficient quantity for their supply, they would probe it anew. 
On August 2nd, both grains appeared to be in a state of fermenta- 
tion, and rapidly tending to decay. On the 3rd, being forty-eight 
hours from the time when I commenced my observations, each 
grain had become a rotten and shapeless mass, and exhibited very 
little appearance of healthy rye. Then, on carefully opening 
the valves of the glume, I discovered in each a small black glo- 
bule, the size of which was rather larger than a pin's head. 
These were situate at the points of the peduncles of the diseased 
grain, which afterwards proved to be ergot. During the first 
four days, after the ergot was discovered, they grew in length 
very near two lines in each twenty-hours, displaying the remains 
of the diseased rye, from the glumes which they had occu- 
pied. On the 12th of August, the ergot had attained its full 
growth. The dimensions of one grain of ergot were twelve lines 
in length, and three lines in diameter ; the other grain measured 
a little less. 

On the 3rd of August, being convinced that the primary cause 


Natural History. i9l 

of efgot was the puncture of the healthy grain by the fly, it 
occurred to me, that, perhaps, it might be produced by such 
means as I possessed. To ascertain this fact, with the point of a 
needle I punctured four grains of rye in the same head, it then 
being in a green pulpy state, and of full-grown size. A dis- 
charge of the juice of the grains was soon discovered from the 
orifice of each. The flies collected as in those cases before men- 
tioned. The result was, that on the fourth day after the opera- 
tion was performed, ergot appeared in the glume, occupying the 
places of two of the punctured grains. The other two grains ex- 
hibited no symptoms of decay, but continued in a healthy 
state. From appearances I am led to believe, that in warm dry 
weather many grains of rye are punctured, which are not ma- 
terially injured thereby. The orifice closes before a sufficient 
quantity of juice has escaped to produce fermentation and de- 
cay. This may, therefore, be assigned as one reason why cloudy 
and wet seasons are so much more productive of ergot than those 
which are fair and dry." 

Not being able at any time to discover, by a microscope, the eggs 
or larva of insects in the rye, General Field concludes, that the 
object of the fly is simply food. The fly is of the hairy or bristly 
species, and deposits its eggs upon animal flesh, either fresh or 
putrid. The culm of rye did not seem affected by the ergot, but 
where there were eight or ten grains of the latter, no sound rye 
occurred in the head, the rye then apparently suffering a severe 
blight. The size of the ergot is in proportion to the number 
of grains in a head ; where there is but one, it is from ten to 
fourteen lines in length, and two or three in diameter ; but 
where there are from twenty-five to thirty grains, and that is 
not unfrequent, they are often not larger than sound rye. — Sil~ 
liman's Jour. ix. "359. 

15. Action of Poisons upon the Vegetable Kingdom. By M. Marcet. 
—A very interesting memoire, by M. F. Marcet, on the action of 
poisons upon vegetable life, has been read to the Societe de Phy- 
sique et d'Histoire Naturelle of Geneva. The object of the 
author in the experiments he instituted was, in the first place, 
to ascertain the action of those poisons which act on animals by 
inflaming and corroding the part with which they come in contact ; 
and in the second place, the action of such poisons, especially 
those of a vegetable nature, which destroy animals by their 
effects on the nervous system. " Until now," the author remarks, 
" plants have been supposed to be distinguished from animals by 
the absence of organs corresponding to the nerves of the latter 
class ; but the results of the experiments tend to prove that they 
are capable of being affected by such poisons in a manner analo- 
gous to that in which animals are affected by them. The experi- 


192 Miscellaneous Intelligence. 

ments were generally made with plants of the kidney bean (pha- 
seolus vulgaris), and a comparison was always made with a plant 
watered with spring-water. 

Metallic Poisons. Arsenic — A vessel containing two or three 
bean plants, each with five or six leaves, was watered with two 
ounces of water« containing twelve grains of oxide of arsenic 
in solution. At the end of from twenty-four to thirty-six hours, 
the plants had faded, the leaves drooped, and had even begun to 
turn yellow ; the roots remained fresh, and appeared to be living. 
Attempts to restore the plants after twelve or eighteen hours, by 
abundant watering, failed to recover them. The leaves and stem 
of the dead plant put into water gave, upon chemical examination, 
traces of arsenic. 

A branch of a rose-tree, including a flower, was gathered just as 
the rose began to blow ; the stem was put into a vessel containing 
a solution of six grains of oxide of arsenic in one ounce of water, 
on the 31st of March. On the 1st of April, the external petals 
had become flaccid and slightly purple, and the leaves began to 
droop ; 10 grains of water, or 0.12 of a grain of arsenic, had been 
absorbed in twenty-four hours. On the 3rd April, the petals were 
more flabby and faded, their colour deep purple and spotted, the 
odour gone, and the leaves faded. During the last twenty-four 
hours it had absorbed four grains of liquid. On the morrow the 
branch was quite dead, and there was no further absorption. Only 
a fifth of a grain of oxide of arsenic had been introduced. Arsenic 
was found, by chemical examination, in the leaves and flower. 
Similar stems placed in pure water had, after five days, the roses 
fully expanded, the leaves fresh and green, and had absorbed 
each, per day, 1 5 grains of water. 

On June 1, a slit of 1 j inch in length was made in the stem of 
a lilac-tree, the branch being about an inch in diameter. The slit 
extended to the pith. Fifteen or twenty grains of moistened oxide 
of arsenic was introduced, the cut was closed, and the stem re- 
tained in its natural position by osier-ties. On the 8th, the leaves 
began to roll up at the extremity ; on the 15th, they had faded 
and doubled up lengthwise, and the branches began to get dry ; 
on the 28th, the branches were dry ; and in the second week of 
July, the whole of the stem was dry, and the tree itself dead. 
Other trees similarly cut, but without having had poison intro- 
duced, suffered no kind of injury. 

On the side of the poisoned lilac was another, the trunk of 
which joined the first a little above the earth. This tree became 
entirely dry, and with similar phenomena, in about fifteen days 
after the first. In another experiment, arsenic was put under the 
bark of a lilac-tree ; in fifteen days, the two nearest principal 
branches were dead and dry ; the rest did not suffer. 

Mercury, — Two or three bean-plants, growing in a pot, were 


Natural History. 193 

watered on the 5th of May with two ounces of water, containing 
twelve grains of corrosive sublimate. Next day they looked un- 
healthy ; the leaves had drooped, and the stalk had become of a 
yellow brown colour ; an equal quantity of the same solution was 
added to them. On the 7th of May the plants were quite dead ; the 
stems were yellow, and the leaves dry and faded. The leaves, put 
into water, gave a solution containing mercury. 

A branch of a rose-tree, with two or three half-expanded roses, 
had its extremity immersed in a similar solution of corrosive sub- 
limate. On the second day, the leaves became discoloured here 
and there, the external petals had faded, but the flower had opened 
a little more ; twenty-four grains of solution had been absorbed. 
Next day, the discoloration was more extensive, and the leaves 
seemed very unhealthy ; on the fourth day the discoloration of 
the leaves was almost complete, and the branch was dry ; the cen- 
tral petals were deepened a little in colour, but had not faded. 
Thirty-two grains of solution, or half a grain of the poison, had 
been absorbed. 

On the 1 Oth of May, a hole was made in a cherry-tree, penetrat- 
ing to its pith ; a few globules of mercury were introduced, and 
the hole closed up, so that air or water could not enter. The 
tree was perfectly healthy on the 10th March, 1825*, not having 
suffered in the slightest manner. 

Tin. — April 13th, a branch of a rose-tree, with two or three 
half-expanded flowers, was put into a solution of muriate of tin, 
of similar strength with the preceding solutions ; on the 1 5th, 
striae of a yellow brown colour had appeared along the fibres of 
the leaves ; on the 16th, the leaves were yellow, and the branch 
dead. The leaves, steeped in water, gave a solution containing 
tin. Muriate of tin affected bean plants in the same manner as 
muriate of mercury. 

Copper. — The roots of a bean plant were withdrawn from the 
earth, and placed in a vessel containing a solution of sulphate of 
copper, in the proportion of the former solutions ; in twenty-four 
hours the leaves of the plant had faded entirely. Reference is 
made to an experiment by Mr. Phillips (Annals of Philosophy, 
xviii. 76), in which a young poplar was killed by watering it with 
solution of copper. A knife, employed to cut a branch off this 
tree, had the copper precipitated on its surface. 

Lead. — The roots of bean plants were introduced into solution 
of acetate of lead, of the preceding strength ; on the second day, 
the lower leaves faded ; on the third day, the plant was dead. 

The same result was obtained with muriate of baryta. 

Bean plants, introduced into solution of sulphuric acid, in three 
times its weight of water, began to droop in a few hours, and in 
twenty-four hours were entirely faded. 

* Probably some mistake. The paper was read 16th Dec. 1824. 
Vol. XX. O 


194 Miscellaneous Intelligence. 

A solution of potash, similarly diluted, produced the same 
effect. 

The roots of bean plants were placed in a solution of twelve 
grains of sulphate of magnesia in two ounces of water. No effects 
were produced at the end of twenty-four hours, and twelve grains 
more of the salt were added ; at the end of forty-eight hours, 
other twelve grains were added, making thirty- six grains in two 
ounces of water ; and yet the plants prospered. The object here 
was to ascertain whether mineral substances, not injurious to ani- 
mals, were also innocuous to vegetables. The same results were 
obtained with common salt. 

Vegetable Poisons. In these experiments the bean plants were 
carefully taken from the earth, and their roots immersed in the 
solutions used. It was ascertained that plants, so withdrawn and 
placed in water, would remain in excellent health for six or 
eight days, and continue to vegetate as if in the earth. As some 
of the poisons used rendered the water in which they were dis- 
solved viscid, a comparative experiment was made in water con- 
taining enough gum to make it more viscid than any of the solu- 
tions used ; the beans thus treated remained fresh and healthy for 
five or six days. Further, all the infusions and solutions used 
were filtered. 

Opium. — (10th May.) The roots of a bean were placed in a 
solution of from five to six grains of opium in one ounce of water. 
In the evening the leaves had drooped, and by the middle of the 
next day the plant was dead beyond recovery. Extract of night- 
shade produced a similar effect, but more slowly. 

Nux Vomica. — (May 9.) The bean plant used was put into a 
solution of five grains of the extract in one ounce of water at nine 
o'clock ; at ten o'clock the plant seemed unhealthy; at one o'clock 
all the petioles were bent at the middle, as if broken ; in the even- 
ing the plant was dead. Another plant, taken from the earth at 
the same time, and left without water, began also to fade in three 
or four hours ; but the leaves only gave way in that time, and not 
the petioles. 

A slit being made (July 15) to the centre of the stem of a lilac, 
nearly an inch in diameter, about fifteen grains of moistened ex- 
tract were introduced, and the wound closed up. On the 28th, 
the leaves of the two largest branches nearest to the wound began 
to dry ; and on the 3d of August they were quite dry. The other 
leaves became dry in the course of the autumn. 

Opium and the nux vomica produce death in animals, according 
to M. Orfila, by acting on the nervous system. Opium appears 
to act upon the brain, and the vomica nut upon the spinal 
marrow. 

Seeds of the Coculus Menispermis. — Ten grains of the extract of 
these seeds were dissolved in two ounces of water. A few mo- 


Natural History. 195 

rhents after the introduction of the plant, the two nearest leaves 
became slightly wrinkled and bent, so as to become doubled. 
When forcibly opened, they again returned to this position. After 
some hours, the leaves began to droop, to twist ; they then be- 
came flabby, and in twenty-four hours the plant was dead, all 
the petioles being bent in the middle. This kind of poison 
appears to act in animals on the spinal marrow, producing tetanus, 
and then death. 

Prussic Acid. — A solution of this acid being used, the petioles 
began to bend in three hours, and in about twelve hours the plant 
was quite dead. All the petioles were as if broken in the middle. 

A drop or two of strong prussic acid, put on to the end of the- 
leaf of a sensitive plant, caused several of the neighbouring 
leaves to close in a few moments. A spoon containing prussic 
acid or the open bottle being held near the leaves, caused them to 
fade. In all these experiments the leaves experimented upon re- 
gained their sensibility only after some hours. 

Laurel'tvater. — In a few moments many of the leaves became 
wrinkled and rolled up, in about half an hour they opened, be- 
came flabby, and in six or seven hours the plant was dead. The 
wrinkling of the leaves varied considerably at different times. 

Belladonna. — A solution of five grains of the extract in one 
ounce of water was used. In a few minutes the lower leaves 
drooped a little, in the evening they had partly returned to the 
natural state ; next morning, they and others had drooped ; on the 
second day the leaves had begun to change colour ; on the fourth 
day the plant was dead. 

Alcohol. — The alcohol was mixed with its volume of water ; the 
plant died in twelve hours. The leaves had faded and were soft. 
When weak alcohol, containing three grains of camphor in half 
an ounce, was used, the plant died in twelve hours ; but, in addi- 
tion to the above appearances, the petioles were bent as if broken 
in the middle. 

Oxalic Acid. — Five grains of the acid were dissolved in one ounce 
of water, and a rose branch put into it. In twenty- four hours 
the rose began to fade, and in forty-eight hours the flower and 
branch were both dead. The plant had absorbed only one grain 
of liquid in the last twenty-four hours, and but the tenth of a 
grain of oxalic acid had been taken up altogether. A bean plant 
in a similar solution died in twenty-four hours. 

Hemlock. — Five grains of extract in one ounce of water. 
Wrinkling of the lower leaves in a few minutes ; these leaves 
dead in twenty-four hours ; the whole plant dead in forty-eight 
hours. 

Digitalis. — Six grains of the substance in one ounce of water. 
In a few moments some of the leaves became slightly Wrinkled at 

O 2 


196 Miscellaneous Intelligence* 

the extremity, in the evening these extremities were dead, and 
twenty-four hours after the whole plant was dead. 

From the whole of these experiments, M. Marcet concludes, 1. 
That metallic poisons act upon vegetables nearly as they do upon 
animals. They appear to be absorbed and carried into different 
parts of the plant, altering and destroying the vessels by their 
corrosive powers. 2. That vegetable poisons, especially those 
which have been proved to destroy animals by their action on the 
nervous system, also cause the death of plants. But as it cannot 
be supposed that poisons, which do not attack the organic structure 
of animals, should affect that of vegetables, so as to kill them in 
a few hours, it appears very probable that there exist in the latter 
a system of organs which is affected by poisons nearly as the 
nervous system of animals. 

Then follow some experiments on the action of certain gases 
on the roots of plants. It is known that if a plant be taken 
from the earth, and its roots be introduced into a receiver of at- 
mospheric air, containing moisture, whilst the leaves are in the 
air above the receiver, there will be found after some hours a 
small quantity of carbonic acid gas. This has generally been 
supposed to be formed by the combination of the oxygen of the 
air with the excess of carbon in the roots. In the following ex- 
periments the roots were placed in different gases, that it might 
be ascertained whether when no oxygen was present, and when 
therefore no carbonic acid should be formed, the plant died more 
suddenly. Six similar bean plants were selected and fixed into 
receivers placed over water, so that moisture should be present in 
the gases, the apertures by which the stems passed out being 
closed carefully. Different gases were then introduced into the 
receivers, and the following results obtained. 

i. Atmospheric air. — The plant remained healthy for forty-eight 
hours, and then gradually faded. 

ii. Hydrogen. — The plant began to fade in five or six hours, 
and was quite dead in fourteen or sixteen hours. The leaves 
were faded and the stem bent. 

iii. Carbonic acid. — The plant began to fade in two hours, and 
was dead in eight or ten hours. All the leaves were faded, and 
the stem bent in the middle. 

iv. Nitric oxide. — The leaves began to bend in about six hours, 
and the plant did not die in less than twelve hours. It appears 
not impossible that a little carbonic acid may have here been 
formed, the nitric oxide being readily decomposable. 

v. Nitrogen. — The leaves began to droop almost immediately ; 
in three hours the skin and upper leaves were bent and faded, 
and in five hours all the leaves were faded, and the plant dead. 
This gas seems most injurious of all those tried. — Ann, de Chim.y 
xxix. 200, 


Natural History. 197 

16. Observations on the Contents of the Digestive Canal in the Foetus 
of Vertebral Animals, by MM. Prevost and Royer. — An abstract is 
contained in the last volume of this Journal, p. 169, of a paper 
by these philosophers on digestion, in which they endeavoured to 
establish that that function resulted from the alternate action of 
soda and muriatic acid, secreted by the alimentary canal upon the 
food. Their object in a second paper or note, the abstract of 
which follows, was to examine the subject as connected with that 
time in the existence of the animal, during which the organs were 
forming, or beginning to act. This examination it appears con- 
firmed their original views. 

The chick in the egg was first subjected to examination. It was 
only on the ninth day of incubation that the organs were in such 
a state as to permit of the fluid in the stomach and intestines being 
collected, only a few drops then being obtained from many indi- 
viduals. At this time the crop or first stomach, the glandular 
stomach and the gizzard contained a transparent liquid, extending 
into threads between the fingers, and slightly alkaline ; tested by 
acids, alcohol, and corrosive sublimate, it, from the precipitates 
formed, appeared to be abundant in albumen. The liquid of the 
intestines appeared to be of the same kind, but was in too small 
a quantity to be easily examined. The waters of the amnios gave 
much less abundant precipitates ; they were clear, slightly yellow, 
and not extensible into threads between the fingers. The waters 
of the allantoides contained no albumen, and were very clear. 

On the thirteenth and fourteenth day the liquid of the glandu- 
lar stomach had increased in quantity, it contained much more al- 
bumen, and coagulated by heat : that portion which was in con- 
tact with the membrane containing it, was white, and had the ap- 
pearance of albumen precipitated by an acid, and in fact when 
put upon test paper, it sensibly reddened it. On opening the giz- 
zard, it was seen that the acid had flowed from the glandular 
stomach into its cavity, by the manner in which the precipitate 
was formed ; abundant near the cardia, but very slight towards 
the pylorus. 

The waters of the amnios coagulated by heat, and were slightly 
alkaline to test paper. Those of the allantoides were slightly 
turbid, from the presence of a portion of crystalline uric acid. 

On the seventeenth day the changes were complete. The fluid 
of the crop was the same, but that of the glandular stomach and 
gizzard was entirely coagulated, and decidedly acid. Particles of 
albumen were found in the intestines, carried there by the peris- 
taltic motion ; their surface was of a fine green colour. There 
was also found a substance containing globules, and of a yellowish 
gray aspect ; it was a mixture of mucus and albumen. The waters 
of the amnios were denser than before. Those of the allantoides 
were of a yellowish white, slightly acid whilst warm from the sac, 


198 Miscellaneous Intelligence. 

and contained both uric acid and urea ; hence the kidneys were 
performing their functions. 

On the twenty-first day, a few hours before the chick would 
have been hatched, the contents of the alimentary canal were in 
such quantity as to allow of other trials on their nature. Decided 
traces of mucus were found in the crop, and free muriatic acid 
was found in the two last stomachs. The contents of the intes- 
tines were liquid in the first part of their course, and of a dull 
cinnamon colour ; in the rectum they were solid, and of a deep 
greenish -brown colour. When treated with alcohol, the latter 
separated the colouring principle, which was remarkable for 
being strongly heightened by contact with the air. The alcoholic 
extract exposed became in a quarter of an hour of a fine deep 
emerald-green colour, being at first only of a pale yellowish- 
green. This change did not take place in close vessels. Acids 
produced the same effects as oxygen ; nitrogen and hydrogen no 
effect. The residue from the alcohol treated with dilute acids 
was separated into two portions ; a coagulated albumen, which 
with certain salts remained, and mucus in considerable propor- 
tion, which dissolved. 

Observations were then made upon a foetus of the mam- 
malia class ; a calf, of the weight of four pounds and a half nearly. 
Its stomach contained a homogeneous liquor of a pale yellow 
colour, transparent, drawing into threads between the fingers, 
and perfectly neutral. It did not change by ebullition or by 
nitric acid, and only slightly by corrosive sublimate, but tannin 
and sub-acetate of lead precipitated it abundantly. Hence it 
contained much mucus, and but little albumen. The waters of 
the amnios were neutral, not adhesive, and gave a less abundant 
precipitate with tannin and solution of lead. 

The small intestines contained a thick matter, formed in part of 
globules. It was of a yellow colour, but slightly adhesive, 
and contained but a small quantity of mucus, much albumen, 
and a colouring matter soluble in alcohol, and having the same 
property as that obtained from the chick. Near the ccecum, the 
appearance of the contents of the intestines changed; they 
there became solid, very adhesive, of a greenish-brown colour, 
and gave much mucus, but little albumen, and the colouring 
matter. The ccecum and rectum were filled with a white sub- 
stance, containing globules without any colouring matter, and 
composed of a little mucus and much albumen. This observation 
is considered as interesting, inasmuch as it shews that the 
secretion of the mucous membrane of the stomach is very dif- 
ferent from that of the mucous membrane of the intestines. It 
also fixes the epoch when the peristaltic motion commences. 

Toward the conclusion of gestation, or about the eighth month, 
the liquid of the stomachs of the calf becomes thicker, more 


Natural History. 199 

adhesive between the fingers, always perfectly neutral. Its 
specific gravity is 101.15. It contains no albumen; its con- 
stituents being mucus in large quantity, an animal matter soluble 
in alcohol and salts of soda and lime. Subjected to the pile, it 
loses its consistency, and deposits a considerable coagulura at the 
positive pole, which, though in appearance resembling albumen, 
has all the properties of very condensed mucus. The first portion 
of the intestinal canal contained a substance analogous to that 
found in the young foetus, but more abundant and more highly 
coloured. The latter portion of the intestines, with the ccecum 
and rectum, contained a solid meconeum* of a greenish-brown 
colour, composed of mucus, albumen, and much colouring matter: 
there were also many hairs dispersed through it; their colour 
was the same as that of the skin of the fcetus : they were also 
found in the mucus of the stomaehs. As similar hairs floated in 
the waters of the amnios, it appear to the author a conclusive 
argument in favour of the opinion that the fcetus swallows some 
portion of the waters in which it is immerged. 

The waters of the amnios were very thick and drawing into 
threads ; they were neutral, and resembled the liquid of the 
Stomachs in the effects of re-agents upon them ; they contained 
no albumen. They never gave traces of the amniotic acid de- 
scribed by MM. Vauquelin and Buonira. This was inexplicable, 
until having left a portion for two days in a hot place, it was 
found very acid, and then, treated according to the process de- 
scribed by those chemists, 170 parts gave about 1 part of pure 
amniotic acid. 

No free muriatic acid was found at any time in the stomach 
of a fcetus of the mammalia class ; its appearance is probably 
very near the moment of its birth, or otherwise it would be 
present before the young animal had received the milk of its 
mother. 

It is then observed, that in a future memoir upon the manner 
in which the foetus is nourished, it will be seen that the foetal 
parts of the placenta form the blood of the new animal, and 
that no mixture takes place between this and the blood of the 
mother : the following observation, terminating the present 
paper, proves this statement. A young foetus of a goat was 
procured, and its blood microscopically examined, and compared 
with that of its mother. The globules of the former had a 
diameter precisely double that of the globules of the latter, i. e., 
two inillemetres (.079 of inch) seen with a magnifying power of 
300, whilst those of the goat were only one millemetre in 
diameter. — Bib. Univ.\ xxix. 138. 

17. Remedy for Effects produced by InJialed Chlorine. — The 
* The name given to the contents of these parts. 


200 Miscellaneous Intelligence. 


B' 


injurious effects which result from the introduction of chlorine 
into the lungs are well known, and as the preparation of this 
substance for its application in certain manufactures is very 
extensive, workmen are not uncommonly suffering in consequence 
of its inhalation. The advantageous use of ammonia is well 
known in these cases, the vapour of it being inhaled, or a little 
of it on sugar being taken into the mouth. It does not, however, 
except where the effect produced by the chlorine has been slight, 
give full relief, probably from the formation of a portion of 
azotane, which is itself very injurious to the lungs ; but M. 
Kostner recommends that at the same time the vapour of alcohol 
should be breathed, which will in an instant dissipate every 
prejudicial action. The spirit of wine is to be dropped on to 
sugar, and held in the mouth. In this way he has made use of 
it for two years with constant success. — Gior. di Fisica. viii. 14G. 

18. Employment of Caustic to destroy the Variolous Eruption.— 
M. Velpeau read a memoir to the Royal Academy of Medicine, 
tending to prove that if the pustules of the small pox are cau- 
terized within the two first days of their appearance, they die 
away entirely ; and if this be done even later, their duration is 
abridged, and no traces of them are left. The caustic he em- 
ploys is a solution of nitrate of silver, in which he dips a probe, 
with which he pierces the centre of each pustule. M. Dumerel 
says that he has been long familiar with this practice, but 
instead of the solution he employed the solid caustic itself. (Ar- 
chives Generates.) — Med. Jour., liv. 170. 

19. Preservation of Anatomical Preparations. — M. Braconnet of 
Nancy has applied the persulphate of iron, in consequence of its 
astringent and antiseptic properties, to the preservation of anato- 
mical preparations, &c. It is very cheap, and combines, with the 
greatest facility, with all the humours and soft tissues of animals, 
and preserves them both from putrefaction and insects. A brain 
which had been plunged for three months in a solution of this 
salt, being put into a warm place, required a considerable time to 
dry it, but without shewing the least sign of putridity ; placed 
afterwards in water, it was still preserved for some time, but did 
not recover its pristine softness. Portions of the liver, spleen, 
lungs, and muscle placed in this salt, have equally resisted destruc- 
tion. — Archives Generates, June. 

Dr. Macartney, of the Dublin University, covers his prepara- 
tion jars with a thin plate of Indian rubber, which is afterwards 
varnished. This is found to be very superior to lead or bladder, 
retains alcohol when used very perfectly, and adapts itself readily 
to the variations of volume in the contents of the jar, from differ- 
ences of temperature. 


Natural History. 201 

20. Physiological Prize Question. — " A general and comparative 
history of the circulation of the blood, in the four classes of ver- 
tebral animals before and after birth, and at different ages." The 
prize, a gold medal of 3000 francs value. Memoirs received till 
Jan. 1, 1827. — Academy of Sciences, Paris. 

21. Salt on the Shore of the Severn.— During the wet weather 
in the month of July last, while walking beneath the cliff of red 
marl, which varies from about sixty to eighty feet in height, at 
Gatcomb, in the parish of Awre, Gloucestershire, on the north- 
west shore of the Severn, I was struck with the white appearance 
of the mud at low- water. On examination I discovered that, from 
the intense heat of the sun's rays, the stratum of mud was divided 
into square sections of various sizes, perfectly dried up, and the 
surface of the whole covered with a very fine salt. I moreover 
found the ledges and hollows of the cliff, where any water had 
lodged upon the reflux of the tide, covered to about the depth of 
one-tenth of an inch with a similar substance ; and in both cases 
the saline particles did not differ perceptibly in taste, as to the 
degree of saltness, from a corresponding quantity of common salt. 
—Letter from Rev. C. P. N. WUton, B.A., Fel. of the Camb. Phil. 
Soc. 


The Burmese imperial state carriage, which has been captured 
in the present sanguinary Indian war, is arrived in this country, 
and is now preparing for public exhibition. It is without excep- 
tion one of the most singular and splendid specimens of art that 
can be imagined, presenting one entire blaze of gold, silver, and 
precious stones. Of the latter the number must amount to many 
thousands, comprising diamonds, rubies, sapphires, white and blue, 
emeralds, amethysts, garnets, cats'-eyes, crystals, &c. The carv- 
ing is of a very superior description, the form and construction of 
the carriage most extraordinary, and the general taste displayed 
throughout so grand and imposing, yet at the same time so chaste 
and refined, as to defy all rivalry even from European workman- 
ship. The enterprise and perseverance of this warlike people 
excite universal attention at this juncture, and the present object 
will prove that their skill in the arts even surpasses their prowess 
in arms, in both of which their proficiency appears hitherto to have 
been equally unknown to us. The carriage stands between twenty 
and thirty feet in height, and is drawn by elephants. 


Vol. XX. 


202 


M 

(A 

■ 


1 

if 

1 


"8 

■ a 

i 


1 


^ii^54|"^*^«B"te"' i, ^i 


g i 

KJ 5 


i 

9 

5 


«l^^>l^^m^l^ll«ig§«§^l 


I' 

s 
2 
1 


8" 

w 


£«£«. f££S$i$$ §?§?$g r^ss §<2$g g ga&&&& 


1 
S 


August, 1825, kept a 
3 ground, and a foot 


-a 


1 


^as5s,ftsa%5.!ja«R5'a^sa ! R!jaa5:5i«s3!asB5 


g »1 HS^ | »1 s'' 21 S S'O S'S s-g s Jfl t| a"S c »^ 


une, July, and 
tiamptonshire. 
ve feet fromth 


4 

CO 

k 


a 


^lI^I*H^«««l^lii^ 


£ 

e 
I 


l^^l^^^l.ll^««^^lglm 


i 

8 
1 


kg 8<§ S |$S|&?£%»ff&2 3*&2 2 ^S 1 2? ?8*g 3£r 


2 tJ « 
| .a -i 
s J i 
1 31 g 

b "g 1 

^ « i 

B - 

M o 


e 
I 

s 


<8 »J?82«| $3g£££g.gi3S 8 2<§ S2?2 2 882<8<2 2 go's 


jEl 


§ 


>8 i/5 m i« 

r'?^r'r'?2- ,?l ' ?, ^0 »OX> OOOa *t<0»3 <tw */330 0O ^m CT:l-*c* to WOO 

1 •>f^«^f'«o^s«o«o t< ti« ii r-001-.ao ooa isiSSSio'Ax iSr^rii--t-- 


I 


hC, m^ i/:co t>-x o; o *■* ci r3 f 1/5:0 r^co o o - c< w* »rtr> r^oo a> o — 

35 : 5 "1 J^:1 o »1 5i »1 = »'g 5| «1 e J< Sj :? 


g 

CO 

1 

1 


1 


J 


i^Hi^^«*lllss|i^^il^i 


§ s 

s 


c 
o 

s 


s « c 

o J 


1 
i 

o 

1 


H 


2 ,25 S5<g ftfi 52 2 3" 2 g& 8 2 SftSS g.^S'SiSS K8 R 

oottcceiffioooooodo'oot-fficirreiicetjd 
r!«scietiseicincor)nnnnnnncii3eiMficienMeiei5ci 


—METEOR 

hermometer 


e 
3 
<3 


§a:sf??siicgsg 2 2 sswzs 2 s^^a^gRs?gg%f« 


is 
is 


*S> 


*fta&s^'*£f;Tay9je!Lftw g.R»5ss rr5>s^<2R 


* 


Art. XVII. 
The! 


« ci co ^ -jyo i^oo Ci o ^ c« r^ ^r »/5to i^oo oi o ^- e* ?o ** into r*a- d o 

NHNHHrtrtHF*NC<C<C»CtC«C<C«C*C»C1« 

It' «^^1.' ^Ifebil'J S v lfebfl' : Spls-b"!! 
si Hill =1 rfHI H ^l 1 -' si &-S1-S5 s I 


The First Course of these Lecttwes will commence on Tuesday, the 11th October, 
at Nine in the Morning precisely. The Second Course will begin on the 
Second Tuesday in February, at the same hour. 

®t)t U0PAI ^njStttUtfott* 

A LUEMA RLE-STREET. 


PLAN 

OF AN EXTENDED AND PRACTICAL COURSE OF LECTURES 
AND DEMONSTRATIONS ON 

CHEMISTRY, 

DELIVERED IN THE LABORATORY OF THE ROYAL INSTITUTION, 

BY WILLIAM THOMAS BRANDE, F.R.S., 

Secretary of the Royal Society of London, and F.R.S. Edinburgh ; Professor of Chemistry in 

the Royal Institution, and of Chemistry and Materia Medico, 

to the Apothecaries' Conipany. 

AND 

M. FARADAY, F.R.S., &c. 


These Lectures commence on the Second Tuesday in October, at Nine in 
the Morning, and are continued every Tuesday, Thursday, and Saturday. Two 
Courses are given during the Season, which begins in October, and terminates 
in June. 

The Subjects comprehended in the Courses are treated of in the 
following order*. 


Division I. 
OF THE POWERS AND PROPERTIES OF 
MATTER, AND THE GENERAL LAWS 
OF CHEMICAL CHANGES. 

J 1. Attraction— Crystallization — Chemical Affinity 
— Laws of Combination and Decomposition. 

i 2. Heat— Its Influence as a Chemical Agent in 
Art and Nature. 

$ 3. Electricity— Its Laws and Connexion with 
Chemical Phenomena. § 4. Radiant Matter. 

Division II. 
OF UNDECOMPOUNDED SUBSTANCES 
AND THEIR MUTUAL COMBINATIONS. 

$ 1. Substances that support Combustion : Oxy. 

gen — Chlorine — Iodine. 
i> 2. Inflammable and Acidifiable Substances: 
Hydrogen— Nitrogen— Sulphur— Phosphorus- 
Carbon — Boron. 
§ 3. Metals — and their Combinations, with the va- 
rious Substances described in the early part 
of the Course. 

Division III. 

VEGETABLE CHEMISTRY. 

§ 1. Chemical Physiology of Vegetable*. 


$ 2. Modes of Analysis— Ultimate and proximate 

Elements. 

$ 3. Processes of Fermentation, and their 

Products. 

Division IV. 

CHEMISTRY OF THE ANIMAL 

KINGDOM. 

$ 1. General Views connected with this Depart- 

ment of the Science. 

5 2. Composition and Properties of the Solids 

and Fluids of Animals. 


§3. 


Products of Disease. 
Functions. 


§ 4. Animal 


Division V. 

GEOLOGY. 

5 I. Primitive and secondary Rocks — Structure 

and Situation of Veius. 

§ 2. Decay of Rocks— Production of Soils— Their 

Analysis— Principles of Agricultural 

Improvement. 

$ 3. Mi