The following abstract contains a brief notice of this as well as of the former part of Mr Stirling's paper, read at last meeting:—

The author gave a short description of the various kinds of cast-iron, and a statement respecting their strengths, and of the uses to which they are more especially adapted, pointing out the discrepancies which exist between chemists as to the quantity of carbon contained in each sort.

Sir Humphrey Davy, by his experiment of melting two pieces of ice by rubbing them together, established the following proposition:—

“The phenomena of repulsion are not dependent on a peculiar elastic fluid for their existence, or caloric does not exist;” and he concludes that heat consists of a motion excited among the particles of bodies. “To distinguish this motion from others, and to signify the cause of our sensation of heat,” and of the expansion or expansive pressure produced in matter by heat “the name repulsive motion has been adopted.”*

The author first refers to a paper by Mr Milne, in the 15th Volume of the Edinburgh Transactions, on the Geology of Roxburghshire, in which the general features of this district are accurately described. The present paper contains a notice of some minuter particulars regarding the formation of the Eildon group and their boundaries obtained by detailed personal examination in 1849.

The author commenced his paper with a few observations on the comparative progress of the different departments of organic chemistry, and remarked that the subject of the polybasic acids is not so completely studied as could be wished, and that he had chosen his subject for investigation in the hope of adding some information on that point.

The author exhibited these spherical concretions, which had formed in a subliming chamber, where carbonate of ammonia from gas liquor was condensed; apparently in consequence of a local whirl affecting the condensing particles. They were formed of acicular crystals, confusedly grouped, without a trace of radiation or of any regular arrangement.

The results of the experiments of M. Grassi on the above subject (Comptes Rendus XIX.) follow sensibly this law.

The compressibility of water is inversely proportional to the density, multiplied by the temperature as measured from the absolute zero of a perfect-gas thermometer, viz.:—a point 274°·6 below the ordinary zero of the centigrade scale, and 462°·28 below that of Fahrenheit's scale.

The author, in the first place, states the equations, which, when used in conjunction with the Tables in the Appendix to the original paper referred to, serve to compute the action of Cornish pumping engines. They are similar in form to those of M. de Pambour, but differ in the expressions for the pressure and volume of steam, and for its expansive action, which the author in the original paper deduced from theory.

The author commenced by referring to the first part of his paper, in which he had determined the existence, among the products of destructive distillation of animal substances, of picoline, which he had before obtained from coal-tar, and of a new base to which he had given the name of Petinine; and had also indicated the existence of certain other bases. On proceeding to the further investigation of these substances, he had been much impeded by deficiency in materials, and had, at length, been compelled to operate on no less than 250 gallons, or about a ton of bone oil.

In this paper the authors, after mentioning the various researches hitherto made on cloves and the substances therein discovered, describe the preparation of the new acid.

20 lb. of cloves are extracted by boiling water, and the decoctions, after being concentrated to six gallons, were acted on by nitric acid, first in the cold, afterwards with the aid of heat. The action is brisk, and irritating vapours are given off, which affect the eyes strongly.

On the 7th of January 1839, I communicated to the Royal Society of Edinburgh a pretty detailed account of the singular mineral and gas springs of Kissingen, in Bavaria, then much less known than at present to English travellers. I refer to this paper, printed in the Edinburgh New Philosophical Journal, April 1839, for the details of the most curious of these, a saline spring called Kunde-Brunnen, which was at that time regularly periodic; a copious and turbulent discharge of brine, mixed with torrents of carbonic acid gas, recurring six or eight times in the twenty-four hours. This phenomenon, exactly as described in my paper, appears to have continued with slight variation ever since, that is, for a period of twelve years, subject, however, to the variation formerly mentioned, that when the brine is actively withdrawn by pumps, for the manufacture of salt, the periods lengthen.

The important researches of Joule on the thermal circumstances connected with the expansion and compression of air, and the admirable reasoning upon them expressed in his paper, “On the Changes of Temperature produced by the Rarefaction and Condensation of Air;” especially the way in which he takes into account any mechanical effect that may be externally produced, or internally lost in fluid friction, have introduced an entirely new method of treating questions regarding the physical properties of fluids. The object of the present paper is to show how, by the use of this new method, in connection with the principles explained in the author's preceding paper on the Dynamical Theory of Heat, a complete theoretical view may be obtained of the phenomena experimented on by Joule, and to point out some of the objects to be attained by a continuation and extension of his experimental researches.

I observed the eclipse from a hill about a mile to the north of Göteborg, situated in latitude 57° 43' 5”, longitude 0h 47m 49s, in company with Mr Edward Lane, Advocate, who kindly rendered me his valuable assistance in making the observations for time. The telescope I used was furnished by Mr Adie of Edinburgh. It has a good object-glass, with an aperture of 2·1 inches, and about 31·5 inches focal length; and the eye-piece employed in observing the eclipse magnified about 28 times.

The author remarked, that the various observers who had seen the eclipse of 1842, gave such generally similar testimony of the place and the size of the red prominences as satisfactorily established them to be some celestial phenomenon. Then as to the question, whether they belong to the sun or the moon, the observers themselves were unanimous in the former view, and the red points then became flaming masses of fire some 40,000 miles in height.

The author, who was in the party of Dr Robinson, Mr Alan Stevenson, and others, mentioned the very kind manner in which the Hydrographical Department had not only lent its instruments, but even caused them to be altered and adapted for the occasion, and also spoke of the liberal conduct of the Board of Northern Lights in conveying the observers to the station selected. This was on the Bue island, on the western coast of Norway, in lat. 61° 9' 42”, and long. E. 27m 0s.

Mr William Lassell, of Starfield, near Liverpool, who has gained a high reputation by his admirable method of constructing large reflecting telescopes, has largely added to his scientific character within the present year (1851), by the discovery of an eighth satellite to Saturn, and determining its period of revolution; and also, by the detection of two new satellites of Uranus.

This paper contains investigations founded on the supposition, that that part of the elasticity of bodies which depends upon heat, arises from the centrifugal force of the revolutions of the particles of elastic atmospheres surrounding nuclei or atomic centres. The author has laid before this Society and the British Association several papers founded on this supposition, which he has elsewhere termed the hypothesis of molecular vortices.

The experiments of M. Regnault having been made by introducing water at a high temperature from a boiler into a calorimeter, containing water at a low temperature, and power exercised by the steam in the boiler in expelling the water was converted into heat by fluid friction, thus producing a rise of temperature in the calorimeter, for which allowance ought to be made in calculating the specific heat of liquid water from each experiment. Mr Joule's determination of the dynamical value of the specific heat of liquid water at low temperatures affords the means of calculating the correction required in each case.

Let p be the pressure of a fluid mass when its volume and temperature are v and t respectively, and let M d v + N d t be the quantity of heat that must be supplied to it to augment its volume by d v and its temperature by d t. The mechanical value of the work done upon it to produce this change is the excess of the mechanical value of the quantity of heat that has to be added above that of the work done by the fluid in expanding, and is therefore

In this communication Professor Stokes described a method which he had discovered, by which he could express, mathematically, the absolute intensity of interfering light, as in the case of the images found in the focus of a telescope pointed to a star, and having a grating over the object-glass. The result was the same as that previously aimed at by Professor Kelland, but the mode of getting at it was shorter.

It was discovered by Peltier that heat is absorbed at a surface of contact of bismuth and antimony in a compound metallic conductor, when electricity traverses it from the bismuth to the antimony, and that heat is generated when electricity traverses it in the contrary direction. This fact, taken in connection with Joule's law of the electrical generation of heat in a homogeneous metallic conductor, suggests the following assumption, which is the foundation of the theory at present laid before the Royal Society.