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of opinion that the rest of the world have a clear interest ia Britain's welfare and prosperity. He remarks that

• Almost all Europe declared against her in a late war, and joined in the wish. for the independance of her American colonies, and perhaps her national superiority, her glory, the extent of her power, and her exclusive patriotism, which nearly resembles that of ancient Rome, may have been the cause of the enmity or jealousy of many other commercial nations. Notwithstanding their prejudices, their i camity or their jealousy, Europe, far from being desirous of the ruin of Great Britain, ought to fear it. Particular and universal in-.. terests are so much blended with each other, and so strictly connecte. ed, that all the members of the great society of Europe, should be as apprehensive of any disasters that may happen to Great Britain, as Great Britain herself

. If by any commotion a fatal change should take place in England, and the genius that decides the fate of nations should doom her to destraction; if weakened by a long and expensive war, and bankrupt from the extent of her national debt, her liberty should be exchanged for slavery; and she became either the prey of a foreign tyrant or a native despot, what would be the situa-. tjon of the rest of Europe?".

The author concludes his observations on the subject of commerce with a very fine and pathetic address in favour of peace. Never was such an address more seasonable than at the present moment, but we fear that it never was likely to be less effectual.

Discussions with respect to the Bankrupt Laws, and to Taxes, close this respectable performance. The frauds pointed out in reference to the former are happily checked in the British code ; while unfortunately every fact, and every doctrine, that can relate to the other, are too well known to British readers, to render it possible that they should derive ruch information on that head from an Italian author.

Though in these pages we have discovered little of original information, we are happy to admit that the love of truth, the zeal for the best interests of mankind, the sound doctrines, the correct notions, and the just ideas which they display, rendered the task of perusing them very far from irksome; and though we think ihat they are better calculated for the state of knowlege which prevails on these topics in Italy, than for a country of such higher attainments as we can boast, still it must be acknowleged that a very large class of men may derive much valuable instruction from the meritorious Jabours of the Neapolitan philanthropist.

ART.

Art. VIII. Transactions of the Royal Society of Edinburgh. Vol. VI.

Part I. 40. gs. sewed. Cadell and Davies. S'Nc INCE the Royal Society of Edinburgh has adopted the plan

of publishing its Transactions in parts of a volume, the quantum of our labour in reporting their contents has in Course been diminished: but it may happen, in like manner, that our satisfaction in announcing papers of importance may also be curtailed. In the present livraison, only three memoirs are inserted: but we shall find that one of them at least will attract by its importance, and gratify by its success,

The first communication is intitled,

A Description of the Strata which occur in ascending from the Plains of Kincardineshire to the Summit of Mount Battoc, one of the most elevated Points in the Eastern District of the Grampian Mountains. By Lieut. Col. Imrie, F.R.S. Edin.--The Grampians stretch from west to cast across the northern parts of Scotland; and at some distance from the eastern termination of the chain, the river North-Esk takes its rise, and, in its course, cuts across one of the ridges, so as to exhibit the different strata of which the mountains are composed. The obe ject of Col. Imrie is to describe the appearances which he discovered in ascending along the bed of the river; and this he seems to have done with great minuteness. The most remarkable circumstances, brought to view in the cleft through which the Esk flows, are the gradual elevation of the sandstone from the horizontal to the vertical position, and the manner in which the strata are intersected by whinstone.

Account of a Series of Experiments, shewing the Effects of Compression in modifying the Action of Heat. By Sir James Hall, Bart.–Our philosophical readers are doubtless acquainted with the grand outlines of the two theories that have divided the suffrages of geologists ; 'according to one of which, water is considered as the grand agent in reducing the surface of the globe to its present state, while the other attributes the same effects to the operation of fire. Although there appear to be no other powers by which the great revolutions of nature could have been effected, yet each of the hypotheses presented difficulties of the most serious kind; so that, while it became easy for the contending parties to overthrow the speculations of their opponents, they were unable to adduce arguments of sufficient weight to establish their own doctrines. It has been objected to the aqueous theory, that the known properties of water will not permit us to consider it as an universal solvent; and even granting that this were the case, it would be impossible Transactions of the Royal Society of Edinburgh, Vol. VI. 399 to accumulate, on our planet, a quantity of it that would be adequate to produce the alleged effect. The objection urged against the igneous hypothesis was scarcely less powerful ; for it is ad. mitted that the properties, which many substances now exhibit, are totally changed by subjecting them to the operation of a high temperature, as is particularly the case with the carbonat of lime. 'In this state of the controversy, a modification of the igneous theory was proposed by the late Dr. Hutton of Edinburgh ; by which he thought that the objections against it would be removed without the assumption of any improbable or extravagant principle. According to his idea, at the same time that the materials of our globe were exposed to the operation of a high temperature, they were also subjected to an im. mense degree of pressure : in consequence of the combined action of heat and pressure, effects might be produced different from those of heat under ordinary circumstances; and especially the carbonat of lime would be reduced to a liquid state, without having its carbonic acid expelled. It was allowed that this hypothesis did not involve any positive contradiction, nor seem to require the operation of any powers inconpatible with the acknowleged properties of the agents employed: but still it wanted the support of experiment. Dr. Hutton, however, supposing that it would be impossible in the laboTatory to imitate the great operations of nature, and probably also in consequence of his habits not being congenial to investigations of this kind, remained satisfied with the facility with which his hypothesis explained the phænomena of geology, without attempting to subject it to any more direct proof.

It was fortunate for the interests of science that Dr. Hutton déclined this task; since it has now been undertaken by a gentleman, who, from his superior skill in practical chemistry, was more competent to it ;, and by whose unexampled assiduity in the prosecution of his object, a series of facts have been disclosed which not only establish the opinion that they were intended to support, but add materially to our knowlege respecting the operations of heat, and point out a method by which its powers may be applied to a variety of new and valuable purposes. Sir James Hall commenced his experiments in the year 1798, and continued them, at every convenient opportunity, until nearly the period at which his paper was presented to the Edinburgh Society. He gives a minute and perspicuous account of all his operations, describing the nature of the apparatus employed, and the results obtained ; the whole composing a train of experiments which, both in the arrangement and the execution, are intitled to unqualified approbation. We must be contented with presenting to our readers a very limited view of them, since they occupy above 100 pages of the publication before us.

readers

The manner in which the experiments were conducted was, to introduce the substance ander examination into a tube of iton, or clas, closed at one end. At this end the body was placed ; on it was rammed a quantity of baked clay, or some substance of a refractory nature ; and then the open end of the apparatus was by different means rendered perfectly air-tight. It is obvious that, according to this arrangement, one end of the tube might be exposed to a great degree of heat, while the other remained perfectly cool; and on this circumstance depended the success of the experiments. When the tube was thus hermetically sealed, the end containing the substance to be examined was placed in the furnace, and heated until the apparatus was no longer able to resist the elasticity of its contents. Both gan batrels and porcelaine tubes were employed : when the former were used, the open end was welded, the materials being previously introduced, and kept cool in the breech. Another method was afterward adopted for rendering the barrel air-tight; viz. to pour on the materials, when placed in their proper situation, a quantity of the fusible metal composed of bismuth, lead, and tin, which is liquefied by the heat of boiling water. While the closed end of the tube was exposed to the heat of a powerful furnace, it was easy to keep the muzzle at such a temperature, that the metal retained the solid state, and the apparatus remained completely closed. When the experiment was concluded, the contents of the barrel were discharged by immersing it in boiling water. Another made, to which Sir James Hall had recourse, was to insert into the muzzle of the tube a quantity of borax, which, by exposure to heat, was vitrified, and thus completely secured the apparatus.

In these different procedures, modified in a variety of ways, according to the circumstances that occurred during the opera-, tron, Sir James Hall performed a great number of experiments on the carbonat of lime; and he found that it might be exposed to a very high degree of temperature, and yet retain the principal part of its carbonic acid. The results which he obtained were, on the whole, extremely satisfactory. The carbonat, which had been inserted into the tube in the state of a powder, was found to be agglutinated into a solid mass; and to approach, in its sensible properties, very nearly to the state of a compact limestone. In some instances, even a tendency to crystallization was perceived ; and the body possessed so much of the texture of marble, as to be susceptible of a fine polish. When the most intense heate were applied which Sir

James

Transactions of the Royal Society of Edinburgh, Vol. VI. 401 James was capable of commanding, the carbonat exhibited evident marks of having been in a state of fusion.

After having thus clearly proved that the effect produced by the joint action of heat and pressure was altogether conform able to the supposition of Dr. Hutton, it remained to ascertain the degree of force that had been employed, and to compare this with the powers exercised in the great operations of nature. By means of a valve, loaded with suitable weights, a calculation was easily formed; and the author was enabled to deduce the following conclusions : " That a pressure of 52 atmospheres, or 1700 feet of sea, is capable of forming a limestone in a proper heat: that under 86 atmospheres, answering nearly to 3000 feet, or about half a mile, a complete marble may be formed: and lastly, that with a pressure of 173 atmospheres, or 5700 feet, that is, little more than a mile of sea, the carbonat of lime is made to undergo complete fusion, and to act powerfully on other earths.'

The conclusions to be drawn from this valuable train of experiments are in the highest degree interesting and important: They decidedly prove that Dr. Hutton's hypothesis is not inconsistent with the acknowleged powers of nature ; and that calcareous substances, when subjected to heat and pressure, are acted on in the way which he supposed would be the case. We are not, indeed, authorized to assert that these events po. sitively have taken place : but it is a great point to have ascertained the possibility of their existence. We must express our earnest hope that Sir James Hall will not suffer his exertions to be suspended; he has opened a new field of research ; and we know not any person better qualified to pursue the track which he has had the sagacity to discover.

A Geometrical Investigation of some curious and interesting Proper, ties of the Circle, &c. By James Glenie, Esq. A.M. F.R.S. Lond. -We confess that we found this paper rather heavy (as the phrase is) during perusal, notwithsthanding the depravation of our taste, which often finds gratification in mathematical discussions of the most abstruse nature. It is not, however, our wish to discourage scientific men from the perusal of this memoir, the author of which is known to be an able mathematician; the same, we apprehend, who published a work called the Antecedental Calculus. The title of the essay adequately describes

its object.

Rev. APRIL, 1807.

Dd

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