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alteration they muft undergo, in order to be disposed towards putrefaction, are unknown to us: the facts are certain, but the manner is yet a secret.

Whatever merit we may allow to the Researches of this fagacious and induftrious obferver of nature, we cannot juftify the verbofity and repetitions which unneceffarily fwell the bulk of this firft volume. We are made to expect four more, in which we are promised, 1ft. An explication of the motions of animals, both voluntary and involuntary, and of the most surprising actions of thofe that walk in their fleep.-2dly, An ample feries of obfervations and experiments upon animals cut into many parts, and on the fenfibility which thefe parts retain after their feparation from the body to which they belong.-3dly, Reasonings and obfervations, defigned to establish (or at least to fet up as candidates) two new attributes of matter, viz. Tendency and Sentiment.-4thly, Remarks on the motions of animals, natural and non-natural, reduced to these two properties. The prefent volume and thofe which we are to expect, muft render this work, upon the whole, interefting to all lovers of natural philofophy, anatomy, and physiology.

ART. IV.

Recueil de Memoires & d'Obfervations fur la Formation, & la Fabriquation du Salpetre.-A Collection of Memoirs and Obfervations relative to the Formation and Manufacturing of Saltpetre. By the Commiffaries, whom the Academy has appointed to diftribute the Royal Premium, &c. Paris.

THE members of the commiffion appointed to examine the memoirs relative to the best method of forming and manus facturing faltpetre, and to which a confiderable premium is: annexed, are Mefits. Macquer, D'Arcy, Lavoisier, Sage and Baumé. It is to thefe very eminent adepts in chymiftry, andin the study of nature in general, that we are indebted for the valuable collection now before us. The Academy, feconded by M. Turgot, thought it expedient to propofe to the candidates for the royal premium, a general view of the fubject which was to employ their refearches, and, knowing that there had been published, in different languages, differtations relative to the manufacturing of faltpetre, they appointed the learned men above-mentioned, to procure tranflations or abridgements of every foreign publication, that could contribute to throw light upon this important fubject. It was thus, that the collection of pieces, now under confideration, was formed by the labours of Mr. Macquer and his affociates, affifted by

This is 4000 livres (or 2001.) to the best memoir, 1200 to the next in merit, and Soo to the third.

feveral

feveral learned men in foreign countries. In forming it they have been more attentive to truths that relate to practice, as alfo to facts and the evident conclufions they announce, than to reasonings of a merely speculative kind; and their collection contains a fufficient extent of practical knowledge to direct thofe, who are defirous of forming artificial beds of faltpetre.

This collection begins by an extract of the works of Glauber, who is not only the firft, in the order of time, that has treated this fubject, but whofe writings, moreover, in the opinion of our Academicians, are the germ, the bud of all the most valuable productions which have appeared fince, in that line of natural science. Accordingly, the authors of this collection give a very large and circumftantial account of the experiments and opinions of Glauber. They, however, obferve, that his ideas ought not to be adopted without a careful examination, as there reigns in his writings, a tone of oftentation, and an affected air of mystery, which denotes a good deal of the fpirit of the alchymift. Glauber proposes several methods of producing faltpetre. Some of them, upon trial, have proved fuccefsful, and have occafioned the establishments, that have been projected and executed, with relation to that object, in Sweden, Pruffia, and other places. Glauber believed, that the fea-falt was convertible into faltpetre, and he points out several methods of producing this change. But as it is certain that faltpetre is to be obtained by the greatest part of various proceffes indicated by Glauber, without the addition of the feafalt to the ingredients which enter into that mixture, it is probable that the faltpetre, which he imagined to be the effect of a Tranfmutation was, in reality, a new Formation. The experiments, which will be made, in confequence of the publication now before us, will probably either ascertain the reality of this tranfmutation, or prove the contrary, and thus remove the doubts that remain hitherto concerning this question.

Stahl was of a different opinion from that of Glauber: he affirms, that the acid which conftitutes the effence of faltpetre, is a modification of the univerfal acid, a combination of the vitriolic acid with the inflammable principle, the Phlogifton, which proceeds by emanation from bodies in a ftate of putrefaction. He indicates accordingly, feveral methods of converting the vitriolic acid into a nitrous one: but the fuccefs of these methods has not, as yet, been ascertained by any Author, and therefore the hypothefis is not fufficiently confirmed.

Lemeri, the younger, endeavoured to prove, that nitre is the product of vegetation alone; but he demonftrated, in oppofition to feveral eminent men, that the air alone is not fufficient to impregnate with faltpetre, earth entirely difengaged from all animal and vegetable fubftances. M. Pourfour du Petit, mem

ber

·ber of the Academy of Sciences, drew up a memoir in the year 1729, concerning the precipitation of fea-falt in the compofition of faltpetre. The council of war in Sweden, published in 1747, an account of the artificial methods of making faltpetre. This is inferted in the work now before us, accom. panied with cuts, and is a kind of elementary treatise, which, however, contains a very circumftantial account of the method of forming faltpetre by Strata, which is ftill followed in Sweden. The year after, the King of Pruffia fell upon another method of multiplying the production of this valuable substance. He ordered each corporation, town, or village, in his dominions to build a certain number of thick walls, composed of earth, ftraw, and other vegetable substances, and to cover them from the inclemencies of the air by a little thatched roof. The fame year the Academy of Berlin offered a premium, whofe fubject was the formation of faltpetre. M. Pietfch, whofe differtation was crowned, affirms, with Stahl, that the acid of nitre is compofed of a vitriolic acid, fomewhat weakened by the phlogiston, which arifes out of animal or vegetable fubftances in putrefaction. In an Appendix, fubjoined to this differtation, 'M. Pietsch fhews, firft, that vegetables are endued with the power of attracting and appropriating all the nitre that is contained in every kind of ground where they grow; and afterwards enters into fome particular details relative to the walls above mentioned.

The Qeconomical Society of Bern published Three Memoirs on the fubject in queftion, which do not speak the fame language. The particular points difcuffed in thefe Memoirs, are, the expedience of employing walls, vaults, ditches or ftrata, for the formation of falt-petre; and the Authors are not agreed on thefe points. In the extract which the Authors of the collection, now before us, have made from them, we find the account of a very successful trial that has been made of one of the methods of Glauber, by M. Neuhaus, who, having amaffed, in a corner of his houfe, for fome time, all the fubftances and materials that were fufceptible of putrefaction, drew from it, at the end of feven years, twelve quintals of faltpetre.

In Sweden, the artificial nitre-works and the branches of knowledge which relate to them, have made a confiderable progrefs. M. Gadd, perceiving the difficulty with which the air penetrated the ditches formed for the making falt-petre, employed with fuccefs the kind of tubes that are used for conveying air into the mines. M. Bergen improved upon this expedient. He propofed placing the earth, defigned for the formation of faltpetre, upon a falfe bottom of planks, at the distance of about two foot from the ground, and piercing these with a great number of holes, that the air might have as free an en

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trance below the mafs as above it. One of the most recent of the Swedish publications on this fubject is the differtation of M.Granit, concerning the means of improving the manufacture of falt-petre in Sweden, and which appeared in 1771. According to him, the circulation of the air is of the greatest efficacy in this matter. He is of opinion that the mixture of fea falt, vitriolic falt, and lime, with the earth employed in thefe operations, beyond a certain proportion, must retard the progress of putrefaction; but our Academicians do not think this obfervation exactly just, though they are highly pleafed with M. Granit's Differtation, and particularly with the detail, into which he enters, concerning the manner of extracting falt-petre from the places where it grows.

We pass over the Memoir publifhed upon this fubje& in Poland about five years ago, by Mr. John Chriflian Simen, because, though his detail is extenfive and interefting, his theory is, nevertheless, vifibly built upon the inflructions mentioned above, as publifhed in Sweden in 1747.

Many able hands are, doubtless, employed at prefent on this fubject, with a view to the academical or rather royal prize. Nay, fome have difinterestedly anticipated this event; fuch as the Count de Milly, Monf. Tronfon du Coudray, and fome other writers, and have published their pieces before-hand. The former defcribes, at great length, artificial nitre-works, which he had feen and examined in Germany; he treats of the faltpetre from the first instant of its formation to its laft calcination and refinement, and as his relations and defcriptions are accompanied with engravings, his Memoir is a fufficient guide to fuch as ftand in need of direction in carrying on a manufacture of faltpetre.

The nitre-works of Malta are carried on in a manner fimilar to those in Sweden: the pyramids are sprinkled with putrid urine, which is gathered, for that purpose, in cifterns. Monf. Clonet has alfo prefented a Memoir to the Academy concerning the manner of extracting faltpetre in India. In certain countries of that great peninfula, all the vegetable foils are, in reality, natural nitre-works. The faltpetre grows in abundance during the dry feafon; it vegetates there, in fome measure, and appears on the furface in fmall Spicula like needles. A great quantity of it may be gathered every year, without any apparent diminution of the produce of the year following. The Writer of this Memoir, upon the authority of M. Perot, tells us that there are, in the kingdom of Cachemire, mines from whence faltpetre is drawn in lumps, as ftones are from a

Count De Milly is a Member of the Royal Academy of Sciences,

quarry;

&c.

quarry; and he affirms that the fame thing happens in the kingdoms of Siam and Pegu. Our Academicians think, however, that in the facts and informations communicated to M. Clonet, the natrum may poffibly have been confounded with nitre. The former, as they obferve, is a mineral foffil fubftance, which is fometimes found in a lump in the inward parts of the earth; but they are not of opinion that we have, as yet, fufficient proofs of faltpetre's exifting in a like manner. M. Clonet acknowledges, that, notwithstanding this natural faltpetre, the Indians encourage greatly its production by artificial methods. The natural faltpetre is abundant in China, nay also in Spain, as we learn from Mr. Bowles's Natural Hiftory of this latter country. The magazines of tobacco, in America, are real nitre-beds. When the mould of the earth, on which the tobacco is placed, is mixed with the refufe of the leaves of that plant, and moistened with the lie of these leaves, a fine faltpetre is foon formed, which appears in a beautiful efflorefcence on the surface.

This collection is terminated by a Memoir of Mr. Lavoifier, one of the Academical Commiffaries; in which he proves that the nitrous acid contains a great quantity of air in a purer ftate than that of the atmosphere, and that it is even poffible to convert the whole of the nitrous acid into an elastic substance, as Dr. Priestley had faid before him.

Such are the heads of the hiftory of the operations and proceffes of the learned in manufacturing faltpetre, which are circumftantially defcribed in the work before us, in order to direct the labours of those who are difpofed to contend for the prize held forth by his moft Chriftian Majefty, and his literary council, the Academy of Sciences.

ART. V.

Ethocratie, ou Gouvernement fondé fur la Morale.-Ethocracy, or a Treatife concerning Government founded on Morals. 8vo. Amfterdam (Rey) 1776.

WHERE is that government? In the head of the Author

in the ardent with of every good man (or which is the fame thing) of every true patriot; and it is to be feared it will remain there, until the reflitution of all things. We beg pardon of certain choice fpirits both among the Ins and Outs, here at home, for this ethical union of patriotifm with virtue, and also for this defperate prediction; but it is upon their authority we fpeak, and they make us prophets against our will, as Eneasdid the Sibyl. Our Author, here, comes in with a frown, and tells us that he propofes nothing chimerical; that every thing, even a reformation of manners and principles, is poffible, provided that the prince be zealously difpofed to restore

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