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them; which refiftance, as it is always proportioned to the velocity of the moving body, may be inexpreffibly great, even in a fluid inexpreffibly rare or penetrable. Hence he infers, that the inteftine motion of hard bodies is quicker than that of foft bodies, and vice verfa. The inteftine motion of folid bodies, however, he obferves, must be harmonical and regular, as in the peculiar modes of this harmony, and regularity of motion, the specific effence of the component corpufcles of different folids confifts. Were any two bodies, fays he, in a juxta pofition conftantly to move, or to be moved, together, always in the fame direction, and in the fame time, we fhould conceive them, if not otherwife diftinguished, to be one body, and not two. It is thus with the parts of bodies: they move or vibrate one among other in fuch directions, and in fuch times, as are compatible with the motion of all; and the reafon they do not feparate is, the refiftance they meet with from the ambient fluid. For whenever this fluid is more rare than the internal medium in which they vibrate, the parts are diffipated, and the tenacity or texture of the body is deftroyed. On thefe principles the Author accounts for the flexibility and tranfparency of bodies; giving a curious mechanical reason why thefe, with many other qualities of bodies, are incompatible with each other: proceeding with great method and regularity to explain the phyfical caules of the impenetrability, inactivity, and gravity, of all bodies.

The Laws of motion, as afcertained by Sir Ifaac Newton, come next under confideration: our philofopher undertaking to demonftrate that, according to the principles laid down, they could not poffibly be otherwife than they are. But the fhort space, to which we muft confine our account of foreign books, prevents us from dwelling longer on this fingularlyingenious tract.

De la Senfibilité, Essai Physique.-A Phyfical Essay on Sensibility. 8vo. Dijon.

At a time, fays this writer, when the long-exploded systems of materialifin are again revived; when the fpirituality of the human mind and the immortality of the foul are denied by writers of the first name and eminence in the philofophical world; it becomes every friend to religion, morality, and virtue, to exert his talents to oppofe that torrent of fcepticism and infideJity which threatens to overwhelm us. It is with this laudable view that the prefent tract is profeffedly written; the author conceiving, if he can make it appear that the moft animated matter is in itself totally deftitute of the leaft fenfation, that the

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notion

notion of matter's being capable of fenfibility, perception, and thought, muft, of course, fall to the ground, as without foundation. To this end, he adduces the later experiments and arguments of the anatomifts and phyfiologifts respecting the feat or fource of fenfation. This, he says, they all agree to place in the irritability of the nerves and mufcular fibres: but he obferves that, unless in cafes of deftruction by lightning, virulent poifons, &c. the animal lofes its life and fenfation long before the nerves and fibres lofe their irritability. This is evident from the contraction of fuch muscles on being pinched or punctured. He cites a number of experiments alfo to prove that, even during the life and health of the animal, its fenfe of feeling is totally absent or loft. Hence he infers that, as the attention of the mind, or a confciousness of memory, is neceffary to make even the groffer parts of the body have any feeling, no delicacy of conftruction can give the more refined parts of fuch bodily matter any kind of feeling whatever; much less fenfibility, reflection, and fentiment. On this confideration. alone he grounds the neceffity of animal nature, and particularly the human frame, being formed or actuated by a spiritual thinking fubftance, effentially diftinct and totally different.

Reponse aux Questions propofées aux Métaphyficiens et aux Geomêtres, &c. Par un Docteur de l'Univerfité de Wilna.—An Answer to the Queftions propofed to the Geometricians and Metaphyficians. By a Doctor of the Univerfity of Wilna. To which is added an Effay on the Nature of Motion, by a Doctor of the University of Heidelberg. 12mo. Liege.

The Queftions, propofed by the learned Doctor of Wilna, as we understand by a fhort preface to the prefent Answers, relate chiefly to the nature of motion at leaft to these only hath the prefent anfwerer replied.

Queft. 1. Have philofophers hitherto entertained a clear and precife idea of the nature of motion? And are they well affured that their ig norance, on this head, hath not made them attribute to motion properties which it has not?

Anf. 1. That our ignorance of the nature of motion, or rather our want of a clear and precife method of expreffing our ideas of it, hath occafioned many mifapplications and ifapprehenfions of the fubject.

Queft. 2. Did Diogenes Laërtius reply pertinently to the objections, propofed by Zeno, against the poffibility of motion, when he filently walked about in the midst of an affembly of Grecian philofophers? And is it not certain that he impofed on himfelf and others, in proving fomething very different from the matter in difpute?

Anfrv. 2. To answer thefe queftions, it is previoufly neceffary to know what Zeno understood by motion, and whether Diogenes enterTained the fame idea; which does not appear to be the cafe. If they

did,

did, they both feem difpofed to quibble and to divert themselves, at the expence of others, by playing at crofs-purposes.

Queft. 3. If a moving object exifts but a fingle inftant in all the places through which it paties, muft not another fuch object, moving twice as faft, exift in the fame places only half an inftant? And what is half an instant? Inftants or points both of time and space are indivisible.

Anfw. 3. This query answers to the ancient quibble of the schools, by which the motion of bodies, or bodies in motion, were denied to have exiftence. "Bodies," faid the quibblers, "cannot exist where they are not; and bodies paffing from one place to another do not exift in either; ergo moving bodies do not exist." Such logic is too impertinent to deferve an answer.

Queft. 4. If, in the defcent of falling bodies, their celerity be conftantly increafed, they must have an inftantaneous velocity [viteffe inftantanée]: but there can be no velocity without motion. There muft, according to this mode of reafoning, therefore, be an inftantaneous motion, which is a contradiction in terms.

Anf. 4. This question is certainly founded on a mere play upon words. If by an inftant be meant any portion, however fmall, of time or actual duration, such instant cannot be instantaneous, or destitute of duration. Inftants or points of time may, indeed, be compared to points in fpace, without abfolute extenfion. But there must be a pofitive distance between any two determinate points, or they would not be divided; they would not be two points, but one. The fame may be faid of inftants of time; there must be fome pofitive duration between any two, or they would not be distinguishable from each other, and would therefore be but one.

Queft. 5. Defaguliers informs us that one half of the fcientific partof Europe, were fixty years difputing about a mere mifconception of terms; a difpute that was reducible to a fimple difference only in words. How could and did this happen? Will any one tell me? or is he defirous that I fhall tell him?

Anfw. 5. If the querift means the difpute about the measure of forces, that difpute is not fettled yet; nor is it reducible to a mere difpute about words. If the propofer of the questions, however, will give his anfwerer his fentiments on the fubject, he will think himself obliged by fuch a reply.

Queft. 6. Ought the profound refpect I bear to the genius of the great Newton to prevent my faying that neither he nor any other philofopher hath demonftrated à priori the laws of the compofition and refolution of motion?

Anf. 6. By no means, if the querift be capable of fupplying the deficiencies in the great Newton. On the contrary, his communicating to the world fuch demonstration à priori, of the laws of the compofition and refolution of motion, would do him great honour, and give equal fatisfaction to the world.

We pafs over the other queftions, as not immediately relative to the fame fubject; at the fame time our readers will obferve, that we have given merely the writer's direct replies, without his illuftrations of the principles on which they are founded.

Journal

Journal Hiftorique du Voyage fait au Cap de Bonne Efperance. Par feu M. L'Abbé de la Caille de l'Acad. des Sc. &c.An Hiftorical Journal of a Voyage to the Cape of Good Hope. By the late Abbé de la Caille of the Academy of Sciences. To which is prefixed, A Difcourfe on the Life of the Author; with Remarks and Reflections on the Cuftoms of the Hottentots and the Inhabitants of the Cape. Paris.

This work, which was firft printed in the year 1763, having been lately reprinted at Paris, the French journalists, as well as our own, have announced it as a new publication. The Monthly Reviewers, in particular, have given a long account of it in their last Appendix, notwithstanding much the fame account was given in that Review near twenty years ago *. There occurs, indeed, fome little difference in the wording of the extracts; of which we fhall inftance one paffage, as a proof of the fuperior attention and abilities of the present, over former, Monthly Reviewers.-Speaking of the Hottentots, the Reviewer of 1763 fays, "The women are cloathed withfheep-fkins, as well as the men; wearing the wool outwards in fummer, and inwards during the winter. They wear one fkin over their fhoulders, the ends of it croffing each other before, and leaving their neck bare; another ikin is fastened round their middle, and reaches down to their knees. Thofe of them who are ambitious to pleafe, adorn themfelves with necklaces of shells: for even in this country the fex have their charms, which they endeavour to heighten by fuch arts as are peculiar to themselves, and would meet with little fuccefs elfewhere. To this end they greafe their faces, necks, and the naked parts of their bodies with mutton fuet, in order to make them fhine. They braid alfo or plait their hair, to give themfelves an additional elegance. An Hottentot lady thus bedizened, hath exhaufted all the arts of her toilette; and, however unfavourable nature may have been with regard to her -shape and ftature, her pride is wonderfully flattered, while the fplendor of her appearance gives her the highest degree of fatiffaction."- -The Monthly Reviewer of 1777, gives the above paffage, in the following terms. "Both men and women are clothed with fheep-fkins, of which the wool makes the outfide in fummer, and the infide in winter. Such of the women as are defirous of pleafing, make necklaces of fhells, knot their hair, and rub their faces, breafts, and all the naked parts of their bodies, with mutton fat, to make them fhine."We do * See Monthly Review, Vol. XXIX. for 1763. VOL, V. Rrr

not

not deny that the firft Reviewers, in faithfully following the original, is rather too verbofe; but furely, in aiming at brevity, the latter has committed a very grofs blunder. That a Hottentot fhould wear the woolly fide of his fkeep-skin inwards in winter and outward in fummer, is natural enough; but that he fhould clothe himself with a fheep-fkin; the wool of which is on one fide of it in winter, and on the other fide in fummer, would be very extraordinary indeed!-During the lapfe of time fince the first publication of this journal, later writers have alto corrected in fome degree the error, the Abbé de la Calle was led into, of fo feverely condemning Kolben; whofe hiftory of the Cape gave the public the first authentic account of the ftate of that country.

Ellai fur le Caratere & les Maurs des François, &c.—Án Effay on the Characters and Manners of the French, com pared with thofe of the English,

The great difference, in the national character of the Englifh and the French, this writer deduces chiefly from their different degrees of attachment to the fair fex. The conclufions, however, he draws from the premises have not always a logical legitimacy.

Lettere Turche, &c.-Or, Turkish Letters; collected and publithed by Etienne Paftor-Vecchio 8vo. Venice.

Thefe Letters are written by a young nobleman of Dalmatia, who ftiles himself Count de Zannovich, and is now on his travels through Europe They appear to be written in imitation of the Perfian letters, and abound with pertinent reflections on men and manners. They have been burnt at Rome, although the writer is no Turk, but a Roman Catholic. Since the publication of these letters, which are dedicated to the Empress of Ruffia, the writer has printed two others addreffed to the prefumptive heir of Pruffia; in which he draws a parallel between the government of the European ftates and that of the Grand Seignior. Being obliged to leave Drefden on account of certain reflections thought to be too fevere on the clergy, he repaired to Berlin, and thence to Potfdain; whither he was in vited by letter from the Prince of Pruffia.

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