of fufion. This we think it most just to present to the reader in his own words. "To reduce the perfpective of the mineral kingdom within the bounds of an academical differtation, we must neceffarily confine it to the general claffes under which minerals are commonly arranged, and a few fpecies of each. And first, as to the calcareous clafs. Stones of this clafs, when perfectly pure, or nearly fo, as fpars and granular marbles, are abfolutely infufible in any degree of heat yet known, as Lavoifier, Geyer, and Ehrman have fucceffively fhewn. On the other hand, the perfect crystallization of the former, and the internal conftitution of the latter, confefledly prove that they were once in a state of perfect folution, and fince they could not be fo in the igneous, they must have been fo in the aqueous fluid; if we fuppofe their particies to have been originally in that state of divifion which actual solution requires, which ftate may as well be supposed to have been their pri mordial ftate as any other, there will be no difficulty in fuppofing them diffolved or fufpended in an aqueous fluid. As to the compact limeftones and marbles, in which the teftaceous exuviæ of marine animals abound, it is evident that if these ftones were ever melted, those would, with them, run into one common mafs, as we have already faid, Other ftones of this clafs are more impure, and mixed with argill and filex in fuch proportion as to be vitrifiable in fuch heats as art can easily produce, yet we never find them in that ftate: a circumftance which clearly excludes all fufpicion of their ever having been exposed to them. "In the muriatic clafs, we fee fteatites and pott-flone, which in their actual ftate have a foft foapy feel, but harden when heated, vitrify in a stronger heat, and acquire a texture and hardness quite different from those they before poffeffed, Steatites often contain 16 per cent, of air and water; thefe characters depofe in favour of an aqueous origin; but ferpentines, of which whole mountains often conlift, demand this origin more loudly; for they are infufible in all but the moft extreme degrees of heat, in which they vitrify and acquire the polifh, texture, and luftre of glass. "In the argillaceous clafs, we meet with argillaceous flates, hornblends, and trapps or bafalts; all of which are in a moderate heat converted into flags, whofe appearances totally differ from that which thefe ftones prefent in their natural itate; and hence they evidently difclaim an igneous origin. Mica has been clearly proved to originate in water by Mr. Nauovarke, 1 Chy. Anu. 1786. "In the filiceous clafs, we have quartz or cryftal in various regular forms, which, if fufed at all, must have been in the thinneft fulion, to be enabled to affume thofe fhapes. Now the ftrongest heat that art can produce is fcarcely capable of producing the flightest emollefcence in pure quartz; how then can we affume that nature, in the moit unfavourable circumftances, could produce à perfect fufion of that fub. ftance? Volcanos afford the most intenfe natural heat with which we are acquainted; yet the most sturdy volcanifts allow it to be infufible in these. In fact it is frequently found in circumftances in which it is impoffible, confiftently with the known laws of nature, to attribute its origin to igneous liquefaction; for inftance, it is frequently, found cryftallized in company with calcareous fpar, fluors, lead ores, &c. on ftones of a mixed nature, as Petrofilex, Hornblends, &c. Now it is well known that though pure quartz or fpars will not melt alone, yet in company with ftones of another kind they will readily melt and unite into one common mafs; when, therefore, they are found in diftinct maffes, close by each other, it is evident that they were not formed by fufion, but in fome other manner; and there is no other than aqueous folution. Of this they bear the marks, for they decrepitate for the moft part when heated, and become opake from the lofs of their watery particles; though the quantity of these involved in their texture be exceeding minute. Have not fhells and chalk, and even water, been found inclofed in filex? The impreffion of fhorls has often been found on the quartz that inveloped it. This laft must therefore have been in a soft state, while the fhorl was in a hard ftate; now this could not happen if the quartz were softened by heat, for fhorl, being infinitely more fufible, must have been in a foft ftate alfo, and concrete long after the quartz: nay, if we credit Mr. Gerhard and others, crystal has been detected in a foft ftate. We have already quoted Mr. Laffone as an eye witnefs of the aqueous formation of filiceous ftones. I fhall only add, that petrofiliceous and other fufible ftones of this clafs have quite a different afpect when they pass through a state of fufion from that which they present in their natural ftate. I alfo pafs over the moffes and other vegetable and animal fubftances inclofed in agates, &c. as our author pretends to account for their prefervation in the midft of the most raging heat by virtue of a compreffion, originating, one knows not how, which prevents their combuftion or charring.' P. 71. That many difficulties alfo accompany the fuppofition of an aqueous folution, Mr. Kirwan freely confeffes. In the actual conftitution of things, he allows, both phyfical and moral, many inexplicable difficulties occur: but he afks, must we not diftinguish thofe which efcape our reason, from those that for mally contradict it? The former he affirms to be the cafe with thofe in the aqueous fyftem, the latter in the igneous. Without attempting to decide between thefe contending philofophers on a point of fo much difficulty, we cannot fail to remark that Mr. Kirwan writes with a correct and comprehenfive knowledge of this fubject, which muft give him an advantage over almost every antagonist; and that the whole paper is of the highest value to those who are attached to fimilar enquiries. V. A Method of preparing a fulphureous medicinal Water. By the Rev. Edward Kenney. P. 83. Sulphur and magnefia intimately mixed, and infufed for three weeks, in the proportion of four drachms of each to a quart of cold water, form a folution of magnefiac liver of fulphur, an ounce of which mixed with a quart of pure water, makes the medicinal water fit for ufe. This has been found of ufe in in the cure of the land fcurvy, the itch, worms, chronic rheu matifm; and appeared to have good effects in a few cafes of fcrofula. VI. On the Solution of Lead by Lime. By Robert Perceval, M. D. M. R. J. A. P. 89. Dr. Perceval found by various experiments that lime acts imperfectly, perhaps not at all, upon lead, without the affiftance of air to calcine the metal. He endeavoured alfo by other experiments to afcertain the action of lime upon lead in dif ferent ftates of calcination. VII. A new Kind of portable Barometer for measuring Heights. By the Rev. James Archibald Hamilton, D. D. M. R. J. A. P. 95. VIII. A Letter to the Author of the preceding Paper, with Remarks and Hints for the further Improvement of Barometers. By H. Hamilton, D. D. Dean of Armagh, F. R. S. and M. R. J. A. P. 117. These papers are too intimately connected to admit of feparation. On the permeability of cork to air, and its refiftance to the paffage of mercury, the plan of this barometer depends, which is thus defcribed by its inventor. "The barometer confifts of a tube not much more than thirty inches long, an ivory cylinder about two inches in length, and upwards of one inch in diameter, open at one end, clofed at the other by a cover that is to be fitted on with a fcrew, fo fine and true as to prevent the escape of any quickfilver when the inftrument is put together. "A found, clean, and porous cork, of about three-fourths of an inch in length, and one in diameter, should be very nicely fitted to enter with a moderate preffure at the bottom of the ivory cylinder, which fhould be turned fo truly throughout that the cork may be pushed up to the extremity of the opening, where there fhould be left a fmall shoulder to ftop the farther progrefs of the cork, and to retain it in its proper place. When the cork is in this fituation it should be carefully bored with a circular file to receive the end of the glafs tube tightly through its axis, fo that the end of the tube may rife beyond it, and project about half an inch into the empty part of the cylin der, and that the axis of the tube, and of the cylinder, may be exactly in the fame right line. "The tube should then be carefully filled in the ufual manner, and the mercury poured over the end into the ivory cylinder till fuch a quantity is admitted as may be fufficient, when the lid is fcrewed down tight, to cover the end of the glass tube in any poffible pofition of the inftrument: to wit, when held either parallel, oblique, or perpendicular to the horizon, a bored mahogany staff with a brafs fcale and vernier, a thermometer cafe, and caps of brass to flide or screw on cach end, is to be prepared to receive the barometer and its at tached tached thermometer, which being firmly and carefully introduced and fitted to their places, the whole is completed and fit for ufe." P. g 97* Dr. Hamilton declares, that from continued and cautious experience, he is certain that these barometers fhew the smallest changes in the weight of the atmosphere, as accurately as those whofe cifterns are open, and that repeatedly tried against the most perfect inftruments, the refults have never varied two inches, in altitudes of above three hundred feet. Dr. H. Hamilton, however, propofes a floating gage and screw as an im provement, and fuggefts fome other alterations. (To be continned.) ART. II. The Life of Hubert. A narrative, defcriptive, and didactic Poem. Book the Firft. Twelve others are defigned to complete the Work. To which are added fome original and tranflated Poems. By the Rev. Thomas Cole, L. L. B. Vicar of Dulverton in the County of Somerfet. 8vo. 190 PP1 5s. Law. 1795. E We have received particular gratification from the perufal of this volume. The poems unite fimplicity with force; and the principal defect feems to be that the author has fometimes been negligent of harmony in the structure of his verfe. We fhould have fuppofed that Mr. Cole had propofed Cowper as his model, but that it appears many of these compofitions were written at least as early as the Talk of that ingenious and justly celebrated poet. We are very defirous to fee the Life of Hubert completed; and, that our readers may know what they have to expect from its final accomplishment, we shall give a sketch of the writer's plan, and a fpecimen of its execution. Mr. Cole traces a boy from his puerile amusements through the four feafons of the year at home, to his removal to Eaton, thence to the univerfity, and to his final fettlement in life. He propofes to difcufs the defects of private and public feminaries, academical ufages, rural retirement contrafted with refidence in the metropolis, and will introduce various epifodical adventures of a ferious as well as ludicrous The firft book is now published as a fpecimen, and it proves the author fully adequate to the task he has undertaken. In his obfervations of nature he appears to be admi rably minute and correct; and if he has not much of the thoughts that breathe and words that burn," he will always intereft, intereft, and often delight his readers. The following defcription is alike recommended by its fidelity and beauty, "The blue expanfe of hyacinthine bloom To rear in white array its mingled flow'rs, Delightful thoughts, fince firft on May-day eve, That croffed our meadow pathway; whilft around, Among |