will best illustrate the different stages of all the processes connected with each substance. Thus here will be seen the different ores, as when first taken from the earth, and the same in all the degrees of purification &c.--the clays in all the stages of manufacture-the substances used in colouring, in the manufacture of glass, &c. &c.

Mineralogists throughout the country, it is hoped, will avail themselves of the permission granted by the Corporation of the University to exchange duplicate specimens.

AMERICAN GEOLOGICAL SOCIETY.

THE annual meeting of this society was held at New Haven Sept. 8th. The following gentlemen were elected officers for the ensuing year

The following gentlemen were elected members of the Society. Henry Seybert, Philadelphia; John Griscom, New York; Dr E. Eminons, Chester, Mass; S. J. Andrews, New Haven; G. T, Bowen, Philadelphia; Lieut. H. Webster,

U. S. Milit. Acad.; Dr J. Porter, Plainfield, Mass.; Dr Edwin James, Philadelphia; Dr Samuel Robinson, Providence; Prof. Jacob Jn. Kott, Schenectady.

FOREIGN.

Samuel Parkes, Esq. of London.

A report was made on the State of the cabinet of the Society, which has been greatly enriched during the past year by the liberal contributions of many of the members.

Valuable additions to the library and cabinet had been also made by its munificent President, among which were the late work of M. Beudant, and Greenough's Geological Map of England.

As the members of the Society reside in all parts of the United States, and with a view of promoting the study of the Geology of this part of our country, and a more frequent intercourse among those who are pursuing it, Dr Webster was appointed a committee to consult the members in the vicinity of Boston on the expediency of holding a semiannual meeting in that city or its vicinity.

Professor Olmstead communicated a highly interesting paper on the Gold of North Carolina, illustrated by specimens. Perkins' Steam-Engine.--The Bibliotheque Universelle for March 1824, contains an elaborate paper on Mr Perkins' Steam-Engine, by a friend of Mr Perkins, which was carried to Geneva, and communicated to the editors, by Mr Church, the American Consul, who had made a voyage to London for the express purpose of seeing Mr Perkins' apparatus. This paper contains the most complete description of the above engine which has yet appeared, and it presents, we believe, the first attempt to explain its operation on philosophical principles. We have been anxious, therefore, more particularly on the latter ground, to examine it, having hitherto looked in vain for any rational account of Mr Perkins' plans, or of those advantages arising from them which have been so confidently asserted as a matter of fact, but, which we confess we have been from the beginning doubtful of,* from what is already known of the nature and principles of heat and of steam. Having read the paper, however, we really see noth

* In connexion with this declaration we refer to this same Edinburgh Journal for July 1823, (see Bos. Jour. vol. 1. p. 287.) where a full account of Mr Perkins' engine, seemingly written by one of the Editors, is published, accompanied with no mean or equivocal praise of Mr Perkins and of his invention. (Eds. B. J.)

ing advanced in it which tends in the least to alter the opin ions we had previously formed; and those who expect in it any reasons to satisfy their curiosity or belief, will undoubtedly be disappointed. In place of that clear and philosophical exposition of causes and effects which such a subject demands, and certainly admits of, if any real discovery has been made, we are here presented with such a mass of mere theories and assumptions, together with such fanciful paradoxes, and downright absurdities, as we believe have seldom been brought forward in the shape of philosophy. Instead of proceeding with a plain statement of experiments, and of consequences deducible from them, or advancing clearly and boldly forward from principles already known, to some great and striking conclusion, the author is continually halting in his career, and bewilders himself in a maze of obscure and unintellibible speculation, ingeniously contrived, one would think, to puzzle himself and his readers. He appears to entertain, in some respects very correct views on the nature of heat, and its expansive force; but he has taken up some strange notion regarding its power of compressing a confined liquid, such as the water in the generator, and of forcing or squeezing out of it," as from a sponge," the heat which it contains. This, and several other notions of a similar kind, seem to have confused his whole ideas of the subject he attempts to explain; so that, though his remarks on other points are, in many respects, sensible and judicious, yet on these topics he appears incapable of reasoning with his accustomed accuracy and vigour of judgment. We are often at a loss to know what he would be at; and all his endeavours to prove what he wishes to demonstrate, are vain. He occasionally proceeds so clearly and methodically with his principles, that you are prepared for some important consequences; instead of which you are landed in some ingenious paradox,-some palpable inconsistency,--some result which turns out, after all, mere assertion or assumption, or not deducible at all from the premises; or, lastly, some obvious truth, in which you are surprised the author can discover any thing new or important.

Having only just received this paper, our limits do not permit us to enter more fully into the particulars of it in the present number. We shall just state, therefore, in proof of what we have said, one or two, as a specimen of the propositions maintained there. 1. It is said, that, in the generator, or high-preasure boiler, the heat is greatest at the top, and decreases towards the bottom, against which the flame and heat of the furnace are chiefly directed; so that while the

temperature of the upper parts of the boiler is at 400°, that of the lower parts next the fire may, in extreme cases, be so low as 40°. 2. Although the water exposed in this manner to the intense heat of the furnace, remains permanently cold, yet, if any crack or opening should take place in the bottom of the boiler within which the water is pressed with a force of at least 400 lb. on the inch, yet no water will issue at the opening. The reason assigned for this, we are unable to comprehend, or to render intelligible. 3. It is proposed to "pump back the heat" into the boiler, after it has done its office of impelling the piston in the cylinder; to pump it back into the generator, and to cause it in this way to act again and again upon the piston; so that, in this manner, the author, in the fervour of his imagination, thinks it but reasonable to expect, that an apparatus of this kind may be constructed, which, when once sufficiently heated, will continue to move for ever, and to drive machinery of itself, without any farther consumption of fuel. On looking into his description of this part of the apparatus, we find the plan consists merely in heating the water of the generator by the waste steam from the cylinder, a plan which has been already frequently proposed, and which is indeed practised to a certain extent in every steam engine in the kingdom.* (Edin. Phil. Jour.)

Method of cleaning Gold Trinkets, and of preserving engraved Copper-plates. The method used by artists for cleaning gold trinkets is the application of a mixture of neutral salt, intended to disengage nitric acid, with the assistance of heat. Dr Mac Culloch recommends instead, to boil the trinkets in water of ammonia, which dissolves the metallic copper of the alloy to a certain depth on the surface, so that after the operation the metal is in fact gilded, nothing but pure gold being visible. In this process the waste of gold, which is dissolved by the acid, in the process usually employed, is avoided.

Dr Mac Culloch observes, "that it is an unaccountable omission of chemists not to have observed that metallic copper is soluble in ammonia. The solution takes place rapidly in the heat at which the water of ammonia boils."

Copper-plates are apt to be injured by laying by; a thin coat of oxide forms on the surface, which is rubbed off by the hand of the workman in the first inking, when the plate is

*In justice to Mr Perkins, our readers will bear in mind that he is not answerable for all the absurdities which are published, in various forms, in the accounts of his engine, by people who are ready to admire whatever they do not understand. [Eds. B. J.]

again called into use; and by repetition of the formation of oxide, and its removal, the fine lines on the plate are soon injured, and ultimately obliterated. Dr Mac Culloch recommends the application of common spirit varnish to the surface when the plate is laid by; it is easily applied, and can be removed when required by spirit of wine.-(Edin. Jour. of Science.)

Mount Rosa the highest in Europe.-Dr Brewster has published, in his new " Edinburgh Journal of Science," from the Memoirs of the Royal Academy of Turin, a translation of an account of the first ascent of the southern summit of Mount Rosa, by MM. Zumstein and Vincent. Having determined, by means of the barometer, that the elevation of the southern summit, which they had gained for the first time, was 13,920 Paris or 14,83564 English feet above the level of the sea, they ascertained, by a trigonometrical measurement thence made, that the elevation of the highest summit of the moun tain was 1680 Paris feet above it, or 15,600 (16,6264 English) above the level of the sea. Thus Mount Rosa is in reality the highest in Europe; the height of Mont Blanc, according to Prof. Tralles, being only 14,793 Paris or 15,7084 English feet. (Philos. Mag.)

New Vesuvian Minerals.-MM. Monticelli and Corelli mention the following minerals as having been sent forth to the surface of the earth during the eruption of Vesuvius in October 1822. 1. Two small pieces of lapis lazuli found in the red sand sent forth on the 24th of October. 2. Several varieties of quartz, resinous quartz, and its passages into a lava composed of amphigene and pyroxene. 3. White and green phosphate of lime in fine hexaedral prisms and acicular crys tals. 4. Perfect cubes of melilite much larger than those of Capo di Bove. The two latter species were found in a current on the sides of Monte Somma above Pollena. 5. Gehlenite resembling that of Tassa. 6. Specular iron in brilliant plates above an inch wide. 7. Oxide of iron in octaëdrons, above half an inch in diameter; the same also in mammelated or fused masses. 8. Antimonial iron. 9. Glass of antimony apparantly containing a small quantity of osmium. (Bib. Univ.)

Seal and Walrus.-Sir E. Home, in a paper read before the Royal Society of London, mentions several facts he has discovered in regard to the walrus and seal.-The first discovery was, that the walrus is provided with means similar to those of the fly, which enable it to walk in an inverted position. The structure of the foot of the fly is described in the Philosophical Transactions for 1916; and on seeing a mutilated