founder at last amidst the simplest doubts and difficulties of real knowlege.

Philofophy, fays Mr. Bonnet, having discovered the impoffibility of her giving a mechanical explication of the formation of organifed bodics, hath very luckily imagined that they must have originally exifted in miniature under the form of germes or rganical corpules. But may we not afk our Author, by what means, and when, philofophy made the difcovery of this impoffibility? Is the fcience of mechanics carried to its greatest perfection? Or, are even its physical principles fo much as known? Who then can take upon them to fay, there is a single phenomenon in nature, that will not admit of a mechanical explication? To this we may add, that philofophy hath no bufinefs to form conjectures, which ferve only to remove a difficulty a degree or two back, without obviating it. It is no difgrace to philofophy, to leave things unexplained, which it has not had the means or the time to inveftigate; but it is highly unphilofophical for men to fupply the want of experiment by conjecture, and fubftitute the vagaries of the imagination for the truths of fcience. When Phyfiologifts have once explained the causes of attraction, of cohefion, of the vis inertia of fofile bodies, and have given a rationale of the laws of motion; it will then be time enough for them to take upon them to fay, whether the formation of organized bodies may, or may not be mechanically explained.

But though we hold the feveral fyftems of generation mentioned by our Author, to be in a great degree vifionary, as we do all immechanical theories in phyfics; yet we cannot deny him the commendations, which are juftly due to his industry and ingenuity; in collecting, and comparing together, the very beft of thofe obfervations, both theoretical and experimental, which have been made on this nice and perplexing fubject. Hence, though we cannot recommend this performance as a treatife of philofophy, we esteem it as an excellent and interefting production in natural hiftory. We fhall juft give our Readers, therefore, a general sketch of its contents.

In the first eight chapters, which, we are told, are juvenile productions, and are extracted from a larger work, our Author treats of the pre-existence of the germes of organifed bodies, their growth and nutrition; remarking particularly on the generation of monfters, and the multiplication of the polypus and other infects. He confiders next the microfcopical obli vations that have been made on the femen mafculinum of feve animals, and analizes Mr. Buffon's new fyftem of organical n leculæ.

In chapter the ninth, he recapitulates the difcoveries

Haller, on the formation of chickens in the egg: deducing fuch confequences from them as ferve to confirm his own theory, and comparing them with the experiments of Harvey; as made use of by Mr. Maupertuis, in his Venus Phyfique.

Chapter the tenth contains remarks on the metamorphofes of infects, and the mechanifin of their growth.

In the eleventh, he fhews that the obfervation made on the formation of chickens effectually deftroys the above-mentioned fyftem of organical elements.

In the twelfth chapter, we have feveral reflections on the difcovery of the Polypus, with obfervations on the fcale of Beings: together with an account of fome uncommon facts relating to vegetables, and the analogy between trees and the bones of

animals.

In this part of the work, our Author makes two quotations, from Mr. Formey and Profeffor Koenig; the one tending to thew that the propagation of infects by dividing them, was known to St. Auguftin, and even fo long ago as the times of Ariftotle; the other intimating that the discovery of the Polypus was foretold by Leibnitz, as a neceffary link in the chain uniting the animal and vegetable creation.

In the fecond volume, the Author goes on to particularife feve ral extraordinary facts, regarding the propagation of infects, by flips and grafts; making his obfervations on the reproduction of earth-worms, water-infects, and on the regeneration of the claws of Lobsters. In the third chapter of this volume, he goes out of his way, as a naturalift, to enter into a metaphyfical dif cuffion about the feat of the foul, in the Polypus, and of the divifion of it, by longitudinally dividing the head. The perfonality, or the Moi, as the French call it, is attached, according to Mr. Bonnet, to the head of this strange Being: but we should have imagined that the Author of the Effai Analytique fur le Facultes de Ame, might have reafoned more accurately on fuch a fubject. The difcovery, fays he, of the origin of the Nerves, hath given us fufficient reafon for placing the feat of the foul in the brain. It is not necellary to fay it refides there in the manner of a body; as it is not a body; but it is prefent there in the manner of a fimple fubitance. If I am afked to define that prefence; I profefs myfelf to be totally ignorant of the internal nature of the foul, that I know little of it, and that only from fome of its faculties." Now, might we not afk Mr. Bonnet here, whether he is certain that the Polypus hath a nervous fyftem and a brain? and, fuppofing he is, what can he mean by a thing refiding in the brain, yet not as a body, but a fimple fubitance? It is prefent, and yet he does not know what that prefence

prefence is. How then does he know it is prefent? By its facul527 ties, fays he. But why may not thefe faculties belong to the very brain he is fpeaking of? Why muft he feek an imaginary fubstratum, when there is a real one? Oh! but, fays he, thele faculties cannot be the mechanical effect of the modification of the animal. Why not? Mr. Bonnet. That is what remains to be proved. As a naturalift, you had nothing more to do than to attend to the motions and other phenomena of this infect; and if you could not account for them, to leave that tafk for others; but, to furnish it with a foul, exifting and refiding you know not how, is all metaphyfical trumpery. But to follow our Author a little farther. 66 exifts in the head of a Polypus; and that this foul hath fenfa"I fuppofe, therefore, that a foul tions which it derives from the organs, with which the infect is furnished. I conceive farther that it hath a fentiment of the prefence of these fenfations; for a foul cannot have any fenfation, without perceiving at the fame time that it hath fuch fenfation. Not that I pretend to fay what this fentiment is; becaufe my foul is not fo made as to feel in the fame manner 29 that of the Polypus: but I can eafily fee, that it is not precisely the fame thing as we call confcioufnefs: Confcioufnefs fupp ing always fome degree of reflection; and we do not attribute reflection to an infect." And yet, we think, he might full 2well impute reflection to this infect as furnish it with a unless he will agree to give a foul to every tree and plant wife. For according to his own fcale, it is next to ime diftinguish between the vegetable that has no foul, an lype that hath one; or between the infect that can In fhort, the perfonality ever c

the animal that can.

Being is a point too difputable for us, to th

of a Polypus.

In the fourth and fifth chapters, Mr. Le vaft diverfity obfervable in the fructificat. plants and animals; and in the fixth ma is to the conclufions drawn from the m

Mr. Needham.

The feventh ant

work, contain farther confideration

ration of animals, with fome im

and propagation of monster.

On the whole, the ca

for inftruction and e

every thing that him

collected and

ject in queftisa.

of being mi

firmed facts, I

moved, where only one unintelligible term is fubftituted for ano ther. Thus, our Author tell us, after his favourite phyfiologif, the celebrated Haller, that "the phyfical caufe of the motion of the heart is its irritability;" and that "the feminal fluid is a fort of ftimulant, which irritates the heart of the embrio, and impreffes cn it a degree of force, which it could no otherwife receive." But what do we learn by all this? while the mode of irritability, and the action of the ftimulus, are unknown, we are as much in the dark as ever. For, after all, there can be no fatisfactory explication of any phenomenon in nature, that is not mechanically deduced from known and intelligible phyfical principles.

However plaufible and ingenious, therefore, may be the hy pothefes of Phyfiologifts in regard to the mystery of generation, they are at belt but mere hypothefes: a number of interesting difcoveries remaining first to be made, ere that important fecre is drawn from the bofom of Nature.

Hiftoire du Siecle d'Alexandre, avec quelques Reflexions fur ceu qui l'ont precedé. 12mo, Amsterdam, 1762. Or, The Hiftory of the Age of Alexander, with fome Reflection on the preceding Ages.

T is difficult to fay whether Truth fuffers most from ou paffion for novelty, or from our prejudices in favour of an tiquity; certain it is, that an Hiftorian runs fome danger from both. A fondnefs for fingularity may lead him into real, as wel as apparent, paradoxes; and an implicit regard to authority, may betray him into the propagation of palpable faifehoods." There is fomething, however, fo becoming a man of genius, in his daring to think for himfelf, that we cannot help applauding the Writer, who lays claim to this privilege, however mitaken he may fometimes happen to be, in deviating from the beaten track of his predeceffors. It is in this point of view. we look upon the ingenious and fprightly Author of the prefent Hiftory; whose youth might, nevertheless, be held a fufficien: plea againft much greater objections, than any of those which we could be induced to make against the firft eflay of so agree able and entertaining a Writer.

In his Introduction, he fets out with obferving the too high efteem in which the memory of Conquerors is held, in general; an obfervation which, if not altogether new, is an inftance, among many others, of this Writer's juft eftimation of human actions and opinions. "If mankind, fays he, were without prejudices,

4

Prejudices, they would be able to form a much better notion of the eulogiums which the world beftows on its Conquerors. They would difcover in them nothing, but the feductive language of weaknes, feeking to difarm Cruelty. They would annex no idea of glory to that title, which fome Kings unhappily conceive to be effential to their greatnels. Hiftory would avenge mankind a little on their Heroes: it would make no great difference between them and thofe monders denominated Tyrants, who are justly become the objects of horror and contempt to poflerity. This way of thinking would be agrecable alfo both to nature and reafon: for, I believe, there never was a Tyrant on earth, whofe vicious caprices were more fatal to humanity than the military valour of an Alexander or a Cæfar. The determinate and tranquil cruelty of a Tiberius, a Nero, and a Domitian, deprived Rome only of a few citizens, in a great number of years; whereas a fingle battle, like that of Arbella and Pharfalia, coft the world many thoufands of men, and depopu lated whole countries.

"Some Hiftorians have lavifned encomiums on Cæfar, for having deftroyed a million of human Beings, in his battles. But if it be really true, that he did fo, never had mankind fo merciless an enemy. Caligula, Commodus, and Heliogabylus, were, in the comparifon, fo many prodigies of clemency and goodnefs. Again, if reafon judges fo feverely of Cæfar, the leaft cruel of all Conquerors, what will it fay of thofe Heroes who are celebrated only by the evils they have occafioned, and whofe glory is founded folely on the deftruction of mankind? And yet, ftrange as it is, we take a delight, in general, to read their hiftory; and we hear the relation of their exploits without horror. We are accustomed, from our education, not to look upon Generals, as refponfible for the deftruction of thole who are killed in battle. As we do not fee them diftinctly atfaffinate the unhappy victims who fall a facrifice to their orders; and as they themfelves run fome rifque, and are expofed to the fame dangers as their enemies, we are cafily induced to forgive them the murders which they feem to commit in their own defence: whereas we are moved with indignation at the cowar dice of thofe princely ruffians who repofe fecurely in t laces, and without hazard to themfelves, ilue th ir crus mands. It is very probable, therefore, that Comp always be invefted with popular reputation; for, v diftinguished by great and heroic qualities, tr will prevent either their contemporaries or ple ing their eyes to the defolation they rea" Deftructive alfo as Wars and Warn to mankind, our fenfible Hißeríu. 1 APPEN,