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count of the habits of the Vultur Aura, or Turkey-Buzzard, in which he exploded the opinion generally entertained of its extraordinary power of smelling. (See preceding Number of this Journal, p. 172-184.) Mr Audubon being present, afterwards shewed to the Society his mode of fixing recently killed birds in various attitudes, against a board marked with squares or division lines, corresponding to similar lines pencilled on the sheet of paper on which the drawing is to be made.

A specimen of the Sword-fish, Xiphias Gladius, seven feet in length, found in the Firth of Forth, and transmitted by Mr Slight, assistant to Robert Stevenson, Esq. civil engineer, was JANUARY-MARCH 1827.

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exhibited, and described by Professor Jameson. The Professor also shewed specimens of Jet-coal, the sort used on the continent for making ornaments, found in Wigtonshire, by Sir Andrew Agnew, Bart. These specimens, he mentioned, were found under peat-moss and above clay, on the property of Sir Andrew Agnew.

1827, Jan. 13.-At this meeting the following gentlemen were admitted members:

NON-RESIDENT.

WILLIAM BALD, Esq. Civil Engineer, Ireland.
GEORGE BENTHAM, Esq. Montpellier.

FOREIGN.

JOHN JAMES AUDUBON, Esq. Louisiana.

Mr CHARLES FRED. HARTT MAN.

Mr Audubon read a memoir on the habits of the Alligator, containing much new information regarding that animal. (See the present Number of this Journal, p. 270, et seq.)-Dr Grant then read an account of the anatomy of the Octopus ventricosus, and exhibited a dissected specimen from the Firth of Forth, of large size, and apparently of full growth.

A stuffed specimen of the Tapir of America was exhibited at this meeting; and the members were then invited by the President to view, in another apartment, some live animals, lately brought from Chili, by the Right Hon. Captain Lord Napier, of the Diamond frigate, particularly the Felis Puma, or American lion.

Jan. 27. At this meeting Dr Grant read an account of the structure of the eye of the Sword-fish, illustrated by a magnified sketch, and by preserved parts of the eye, taken from the animal lately killed in the Firth of Forth.

The Rev. Dr Scott of Corstorphine then read a dissertation. on the Saphan of the Sacred Writings, proving it to be the Hyrax Syriacus, although rendered coney in our common version.

Feb. 10.-At this meeting the Secretary read a communication from the Rev. William Scoresby of Bridlington, containing descriptions of some remarkable Rainbows. (Printed in the present Number, p. 235, et seq.)

Professor Jameson then read Mr William Bald's geological

survey of Clare Island, on the west coast of Ireland, illustrating the same by maps and sections executed by Mr Bald.

The Professor then gave a general descriptive account of a splendid series of the Pheasants and Peacocks of India, specimens of which were placed on the table. A stuffed specimen of a Persian Sheep, presented to the Royal Museum by James Gibson Craig, Esq. was also exhibited. Mr Audubon laid before the meeting several specimens of the coloured Plates of his great work on American Ornithology, executed by Mr Lizars of this city; and they excited general admiration.

SCIENTIFIC INTELLIGENCE.

NATURAL PHILOSOPHY.

1. Repulsion of Heat inversely as the square of the distance. -Sir Isaac Newton has shewn, Principia, Lib. ii. Prop. 23 *, that if the repulsion between the particles of a gas were inversely as the square of the distance of their centres, the cube of the pressure would be as the fourth power of the density, and vicc versa. Now this is precisely the relation which we formerly saw should subsist between the pressure and density of air containing a constant quantity of heat, if, as appears from experiment, the specific heat under a constant volume be to that under a constant pressure as 3 to 4+; and, therefore, whilst the quantity of heat connected with each particle of air is constant, the repulsion between them is inversely as the square of their distance. This being the law common to magnetism and gravitation, scarcely leaves a doubt that the true ratio is that of 3 to 4. It is also the actual law of gaseous repulsion; for that first given by Newton, and generally adopted, making the repulsion inversely as the simple distance, really compares the re

* Some allege that this proposition requires each particle to act only on those next it; but it holds equally true, whilst each acts on a constant number, however great, if similarly situated.

+ See equation (C) page 336. vol. i. of this Journal.

Any tendency in the particles to gravitate toward each other, would not

affect a law similar to its own.

pulsions in cases where not only the distances, but the quantities of heat are different. The above principle of the repulsions, being inversely as the square of the distance, might easily be shewn to accord with the law of temperature and the law of Boyle. Any variation in the quantity of heat, will, cœt. par., produce proportional variations in the logarithms of the repulsions. Perhaps the same property belongs to magnetism or electricity, if not to gravitation itself. HENRY MEIKLE,

2. The Beech-Tree a Nonconductor of Lightning.-Dr Beeton, in a letter to Dr Mitchill of New York, dated 19th July 1824, states, that the beech-tree (that is, the broad-leaved or American variety of Fagus sylvatica) is never known to be assailed by atmospheric electricity. So notorious, he says, is this fact, that, in Tenessee, it is considered almost an impossibility to be struck by lightning, if protection be sought under the branches of a beech-tree. Whenever the sky puts on a threatening aspect, and the thunder begins to roll, the Indians leave their pursuit, and betake themselves to the shelter of the nearest beech-tree, till the storm pass over; observation having taught these sagacious children of nature, that, while other trees are often shivered to splinters, the electric fluid is not attracted by the beech. Should further observation establish the fact of the nonconducting quality of the American beech, great advantage may evidently be derived from planting hedge-rows of such trees around the extensive barn-yards in which cattle are kept, and also in disposing groups and single trees in ornamental plantations in the neighbourhood of the dwelling-houses of the

owners.

HYDROGRAPHY.

3. Silica in Springs is dissolved by means of Carbonic Acid. -Dr Karsten remarks, that, if so feeble an acid as the acetous, is capable of dissolving silica, it is not improbable that the carbonic acid may have the same property. This conjecture he has confirmed by experiment. The experiment may be made as follows. Decompose a portion of liquor silicum by means of a superabundance of any acid, the muriatic, for example, and neutralize the clear fluid with carbonate of ammonia, at the lowest possible temperature. The carbonic acid evolved by this

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