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he fufpended a pewter-plate with 16 eggs on the conductor of the electrical machine, and kept his apparatus during eight days, and as many nights, in a degree of electricity as near as poffible to that which correfponds (if the expreffion may be allowed) with 32 degrees of heat. The fuccefs of this experiment confirmed the conjectures of M. ACHARD. Opening one of these eggs at the end of the firft 48 hours, he perceived a fmall beginning of the formation of the embryo, and he difcerned plainly the progrefs of this formation by opening an egg every day; but an accident that difconcerted his apparatus prevented his continuing his electrical operations to the birth of the chicken. This fuccefsful beginning, however, will encourage new trials.

Memoir. Concerning the Mandragora, or Mandrake. By M. GLEDITSCH.-Philologifts, naturalifts, commentators, and wags have contributed to the propagation of the filly or indecent fables to which this plant has given occasion, and which M. Gleditsch has expofed as they deserve, in this learned Differtation.

Memoir. Concerning the Colours of Vegetables. First Part. By M. ACHARD. Philofophers and chemifls are not yet agreed about the true caufe of the colours of vegetables; nor has this matter been treated hitherto with the attention it deferves. Hales has recourse to fubtilized aerian principles, which feem too thin to be grafped; Becher, Stahl, and Henckel to iron or copper; and Pott to the phlogifton, in order to account for the phenomenon in queftion. After thefe comes Count Mouroux *, who, by a great number of experiments, has undertaken to prove, that flowers contain a fixed colouring PRINCIPLE, which exifts even in the ashes to which they are reduced, and communicates to the vitrifications in which these ashes are employed, the colour of the refpective flower, and of all the other parts of the plant. But after him comes M. ACHARD, who repeated all his experiments with the most curious attention, and the refults he obtained from them were quite contrary to those of Count Mouroux. The detail of thefe experiments, as they were made by M. ACHARD, is exceedingly interefting. This ingenious Academician could never find the leaft refemblance or analogy between the colour of the vegetable fubftance before its incineration, and that of the glafs into whofe compofition its afhes entered as an ingredient. But if he pulls down an hypothefis built upon ill-conducted experiments, he means to establish another upon more folid foundations: in the fecond Part of this

His Memoir entitled-A Phyfico-chemical Examination of the Colours of Flowers, and of fome other vegetalle Subflances, is inferted in she 5th volume of the Mifcellanea Taurinentia. Memoir,

Memoir, as yet unpublished, he defigns to fhew, that the colours of flowers and vegetables, in general, proceed only from the combination of their conftituent parts, and from their degree of fermentation, which, according as it varies, produces, of neceffity, a difference in the arrangement of the parts of vegetables :-hence our Author will be led to explain the cause of the changes which the abfence or prefence of light produces in the colour of vegetables and of other natural bodies.

Memoir. Concerning the Measure of the Salubrity of the Air, containing alfo the Defcription of two new Eudiometers. By M. ACHARD. It appears from the accurate experiments and the important discoveries of Dr. Priestley, that the principal use of the air, in refpiration, is its difcharging the lungs of the phlogifton; fo that when the air is faturated with phlogifton, and confequently cannot charge itself with a larger quantity, it becomes unfit for refpiration. The lefs, therefore, that the air is charged with phlogifton, the fitter will it be for respiration; and proportionably more wholefome; and the eudiometers are defigned to ascertain the degree of falubrity that arises from the greater or leffer quantity of phlogifton, with which the air is charged. The eudiometers of Landriani and Magellan are ingeniously conftructed; but the employment of them requires preparations which cannot be made every where; befides, a portable inftrument of this kind, which, by an easy operation, can enable us to determine the degree of the phlogiftication of the air in any place whatever, is an object of confequence. This circumftance gives a peculiar advantage to the invention of our Academician; for a particular defcriptive account of whofe eudiometers, which would be scarcely intelligible without a fight of the plates, we must refer the curious to the Memoir itself, and the figures which accompany it.

Memoir. Concerning the Caufe of the Afphyxia, and the propereft Remedy for that Disorder. By M. ACHARD. As the refpiration of mephitic vapours is the circumftance that produces the afphyxia, an examination of the cause that renders thefe vapours noxious will naturally lead to the true source of this diforder. The observations and experiments, made by this indefatigable Academician, on rabbits, finches, cats, and other animals, prove, ift,--That it is to the phlogifton with which mephitic vapours are charged that we must attribute their noxious qualities-2dly, That the phlogifton, which exhales from the lungs, and is obftructed in its paffage, produces the afphyxia3dly, That the accumulation of phlogifton in the lungs is the cause of the numbness in the nerves, and of the fufpenfion of refpiration during the asphyxia-4thly, That of all the remedies herto employed against this disorder, the immiffion of dephlo

gisticated

gifticated air is that which promises the most fuccefs, because it attacks the evil in its principle and cause.- Our Author's apparatus for tranfmitting this air into the lungs is well contrived. MATHEMATICS.

Memoir. Concerning the Determination of the Orbits of Comets after three Obfervations. By M. DE LA GRANGE. Two Memoirs. This celebrated Academician analifes the different methods, that have been hitherto propofed, of refolving the problem here mentioned. Sir Ifaac Newton was the first who attempted it; but the folutions which he left behind him were imperfect, and thofe who fucceeded him in the fame undertak ing did little more than diverfify and reduce to a greater fimplicity the methods pointed out by him, without rendering them more exact or commodious for practice. Our Author expofes the defects of all these methods; fhews, that the problem can only be folved by approximation, and points out the manner of folving it in this way.

Memoir. Concerning the Theory of Telescopes. By the fame. The general canons to which Meffrs. Cotes and Euler attempted to reduce the theory of telescopes, are here approximated and compared together, by M. LE GRANGE, and are improved by new and interefting researches, which tend to reduce this theory to a greater degree of fimplicity.

Hiftorical and Aftronomical Inquiries concerning the Polar Star, and the Conftellations that are the nearest to the Poles. By M. JOHN BERNOUILLI. Three Memoirs.

Inquiries concerning the Method of finding directly the Equation of Time. By M. SCHULZE.

SPECULATIVE PHILOSOPHY.

Inquiries concerning the Unities of Nature. By M. BEGUELIN. First Memoir. We have already feen where all the researches of this kind terminate, or rather we have feen that they do not terminate at all-for, inftead of coming at the real elements of bodies, they only arrive at the atoms of Leucippus, which come fhort of the mark, or the ideal monades of Leibnitz, which go beyond it, and like the arrow in the Eneid, vanish into air. Prefenting to us thefe old fyftems, with new names, and fome new modifications, they make us think, that we are getting on towards the principles of things; whereas we remain still pretty much in the fame place. There is no guide whofe penetration and metaphyfical talents promife fairer to bring us fome fteps nearer to the fountain-head than those of M. BEGUELIN: and certainly there is an uncommon degree of acutenefs in the Memoir now before us.

By the Unities of Nature, Mr. B. underftands neither abftract unities, nor the phyfical, individual beings, which are the ob jects of our fenfes, but all those primitive beings, whose organi-` App. Rev. Vol, Ixiv.

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zation is indeftructible, though fufceptible of different modifica tions, by its own powers, and thofe of other organized beings. In a word, every unity of nature is a machine, immediately created by the Deity, according to our Academician; and thus we think that he has pofted himself between the Monadifts and the Atomifts. How long he will maintain this poft, we cannot tell; we do not mean either to interrupt him in the poffeffion of it, or to share it with him. But there is fomething fo mafterly and ingenious in his manner of fortifying and defending it, that what he has faid may be read with profit, though we neither adopt nor reject his hypothefis. It is certain, that thefe organized unities, cannot be objects of obfervation. It cannot, however, be faid, on the other hand, that their existence is impoffible; and this is the only conceffion which our Author requires at his fetting out in this dark and intricate difcuffion. Indeed, analogy gives him a full right to this conceffion, at leaft; fince, as he obferves, all individual beings are organized even in their fmalleft particles, as far as the eye, aided by microscopes, can carry its infpection. It is probable, fays he, that this organization goes much farther than we can fee; and that, at length, the decompofition of fecondary machines must be refolved into primitive ones, whofe organization is the immediate work of the Creator, and which are, confequently, true elements, the real unities of nature, beyond which analyfis cannot go.

This hypothefis furnishes Mr. B. with folutions of fome of the most difficult queftions that have hitherto divided the metaphyficians. Eleven of the feare amply difcuffed in this firft Memoir. They are as follows: 1. Is matter infinitely divisible, and in reality infinitely divided?--2. Are organical beings infinitely fubdivifible and infinitely fubdivided? The Reader may judge of Mr. B.'s manner of anfwering thefe queftions by the following judicious obfervation: Infinity, whether of number or space, is a conception merely geometrical; it is an imaginary notion; and it we confider it otherwife than as the expreffion of a term or limit to which our narrow understanding cannot reach, it is a palpable contradiction, fince it fuppofes and annihilates limits at the fame time. This fhews, that infinite has no fort of relation to created fubftances, which are effentially finite. An important truth!-3. Does not each unity of nature comprehend an infinity of different parts? No-for very fatisfactory reasons alleged in the answer to the preceding question.-4 Is not each part of an organifed primitive being, itself an organised being, pill more fimple, and fo on, without end? No-for then the organifed primitive being would be no longer primitive, or, in other words, it would not be what it is. This queftion can only be refolved by banishing from real and finite beings the here improper and contradictory idea of infinity.-5. Are not all the parts of primi

tive unities compofed originally of parts perfectly fimilar and homogeneous? The difcuffion of this question (fays our Author) is of no moment; it is enough to know, that each part has its pecu-' liar nature, its diftinctive properties, its aptitude to the ufes it is defigned to ferve.-6. Are the laft or fmalleft parts conceivable of the primitive unity material or not? If (fays Mr. B.) you understand by matter, a homogeneous mass, which is only extended and impenetrable, without any other property or quality whatever, then, neither the primitive unities, nor their parts, are material. Thefe unities have, indeed, extenfion, because their parts are diftinct; and impenetrability, because two or more of these parts cannot occupy the fame place; but as they come from the hand of the Creator, organifed, endowed with an active power, and poffeffed of all the qualities that are requifite to produce the fucceffive effects which refult from their nature, the idea of mere matter, as above defined, is not applicable to them. The entire machine, conceived in the Divine Mind, must have received at once its existence by a fingle act, and thus its nature spurns analytical inveftigation. The primitive unity does not resemble Pygmalion's ftatue, whofe compofition was effectuated by repeated strokes of the chiffel on a rude and fhapeless mafs of marble; it rather resembles the form of Minerva, who iffued forth, inftantaneoufly, with all her armour, from the brain of Jupiter. If this be true with refpect to the primitive unities, it is equally applicable to all their parts.7. Are the last or Smallest parts of the unities of nature without fize, extenfion, or figure? They are the elements of fize, extenfion, and figure; as, in arithmetic, unity is not number, but the element of all numbers whatever. See the Memoir. -- 8. Might not the Deity have created the fimple, elementary parts of the unities, and deduced from them thefe primitive unities by fome general laws of nature? What the Deity could or could not do, our Author thinks it rash in us to determine; he, however, modeftly puts a negative upon the question, and gives his reafons, for which we refer to the Memoir, as (contrary to what ufually happens) we are fomewhat in hafte.-9. To have recourse to the IMMEDIATE CREATION of the unities of nature, is not this cutting the knot, inftead of loofing it? No-for in all investigations of a cosmological nature we must come, at laft, to immediate creation.-10. Does not the analysis of compound beings lead us more naturally to the monades of Leibnitz, or the fimple elements of Wolf, than to the primitive unities or automata of nature? No-and, hypothefis for hypothefis, we think that of our Academician preferable to thofe of the two great German birds of Minerva; fince on his hypothefis the corporeal univerfe has a true and real exiftence, conformable to the reports of our fenfes and feelings, and is not a mere ideal phenomenon, as it must be in the fyftems of LeibLi2 nitz

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