endeavours to fhew, by feveral experiments, and what he thinks to be natural deductions from them, that an electrified thundercloud ftriking into the earth, not only differs folely in degree, as to its effects, from a common infulated conductor of an electrical machine, charged by an excited globe, and fpontaneously darting forth luminous pencils, or giving sparks to a body in the neighbourhood of it; but that the fparks or explofions in both cafes are caufed by the fhock or collifion of two currents of matter, meeting each other in oppofite directions. We have not room to explain the Abbe's reafonings on this fubject, which will be but little relifhed, we believe, by thofe who are acquainted with, and have attentively confidered, the very natural explication of these phenomena by Franklyn, Wilke and pinus, or the obfervations of Signior Beccaria: befide, the language used by the Abbé with regard to the explanation of electrical phenomena is fo very different from that of other electricians, that, had we room, we should defpair of rendering his reafonings on this head intelligible. In the fecond part of this memoir, after treating pretty largely of feveral incidental matters relative to his fubject, and explaining, according to his own theory, the phenomena attending fome remarkable thunder-ftorms, the Abbé treats of the means of preferving men and buildings from the ravages of the electric matter: but here indeed he gives us poor comfort. Our Author was very early in declaring his opinion of the inefficacy of the methods propofed for conducting the electric matter of 2 thunder-cloud, with fafety, to the earth; and in strongly fuggefting how improbable it was that the large t rrents of electrical matter, in motion during the ftorm, could be carried off by being filtered, as it were, drop by drop, through a flender piece of metal. He ftill perfils in the fame fentiments. Our pointed rods, he says, may juftly be confidered as electrofcopes, that is, they may very readily inform us when it thunders, or is going to thunder; but he thinks them perfectly inadequate to the fervice expected from them; and affirms that they are more likely to draw down the matter of lightning upon our heads, than to preferve us from it. The juftice of this conclufion he fuppofes to be fufficiently proved by the death of Profeffor Richmann. According to the Abbé, therefore, it must thunder on, and the lightning must take its courfe, notwithftanding any thing we can do to modify or direct it. Few unprejudiced electricians will, we believe, with regard to this matter, be of opinion with the Abbé; who takes no notice, in this memoir, of the numerous experiments which militate against it, nor produces any which in any degree confirm it. The inftance adduced of the death of Profeffor Richmann is certainly ill chofen, as it is very evident, that, had not the profeffor brought his body into fuch a fituation, with regard to the wire of his apparatus, as to become the nearest conductor communicating with the floor, the whole electric matter would undoubtedly have been carried off through a metallic conductor of a proper thickness, reaching to the earth (with or without an explofion, according to its quantity) without prejudice to him or his house. We might as well declaim on the dangers attending a channel cut with a view of preferving a man's houfe, by carrying off the waters of an inundation, because the owner may happen to flip his foot and be drowned in it, as object against the ufe, or deny the fafety of thefe electrical drains, becaufe a curious and incautious philofopher has been killed by firft damming up the torrent, and then running his head into it. By certain of nature's operations, which remain hitherto unknown to us, except by their effects, the electrical equilibrium between the earth and the clouds, as well as that between one part of the earth and another, is liable to be frequently disturbed; and certain fudden, violent and dangerous explosions are the confequence of its being reftored. The operations by which this equilibrium is broken we cannot prevent; but it appears to be in our power, if not to keep the balance even, at least to prevent the afcending arm from violently kicking the beam, and knocking us on the head. In fhort, to return to our former metaphor, with regard to the channels which we provide for the carrying off the electric matter, it must be our own fault, if we do not make them large enough, or if we tumble into them, when we have made them. We could not help fmiling at the Abbe's management and adroitnefs in trimming between his two characters of a church man and a philofopher, when treating of the many real or ima, he treats ginary prefervatives against thunder. Speaking of the efficacy where the bells were not rung, efcaped. We shall not extend this article by an enumeration of the human means recommended by the Abbé. A few pounds of iron, properly difpofed, we think, are fuperior to them all. We fhall only obferve that the Abbe's prefervatives are chiefly founded on the principle of infulation, or refifting the electric matter, by the affiftance of nonconductors, or electrics: It appears to us on the contrary, much more prudent not to contend with fo powerful an antagonist; but to provide for it a peaceable entry into and paffage through those conductors which it is known moft to affect, and which happily are very easily procured. II. On the extraordinary degrees of heat which men and animals are capable of fupporting: by Monf. Tillet. Boerhaave, in his Chemistry, relates certain experiments made with great accuracy by the celebrated Fahrenheit and others, at his defire, on this fubject, in a fugar-baker's office; where the heat at the time of making the experiments was up to 146 degrees of Fahrenheit's thermometer. A fparrow fubjected to air thus heated, dyed, after breathing very laboriously, in less than seven minutes. A cat refifted this great heat fomewhat above a quarter of an hour and a dog about 28 minutes: difcharging before his death a confiderable quantity of a ruddy coloured foam, and exhaled a stench fo peculiarly offenfive as to throw one of the affiftants into a fainting-fit. This diffolution of the humours, or great change from a natural ftate, the profeffor attributes not to the heat of the ftove alone, which would not have produced any fuch effect on the flesh of a dead animal; but likewise to the vital motion, by which a ftill greater degree of heat, he fuppofes, was produced in the fluids circulating through the lungs, in confequence of which the oils, falts, and fpirits, of the animal became fo highly exalted. Meffieurs Du-Hamel and Tillet having been fent into the province of Angoumois in the years 1700 and 1761, with a view of endeavouring to deftroy an infect which confumed the grain of that province, effected the fame in the manner related in the Memoirs for 1761, by expofing the affected corn with the infects included in it, in an oven where the heat was fufficient to kill them, without injuring the grain. This operation was performed at Rochefoucault, in a large public oven, where, from œconomical views their first step was to affure themselves of the heat remaining in it on the day after bread had been baked in it. This they did by conveying into it a thermometer on the end of a shovel, which on it's being withdrawn indicated a degree of heat confiderably above that of boiling water: but M. Tillet, convinced that the thermometer had fallen feveral degrees in drawing to the mouth of the oven, and appearing under fome embarraffment on that head, a girl, one of the attendants on the oven, offered to enter, and mark with a pencil the height at which the thermometer ftood within the oven, The girl fmiled on M. Tillet's appearing to hefitate at this ftrange propofition, and entering the oven, with a pencil given her for that purpose, marked the thermometer, after ftaying two or three minutes, standing at 100 degrees of Reaumur's fcale, or to make ufe of a fcake better known in this country, at near 260 degrees of Fahrenheit's. M. Tillet, who does not feem on this occafion to have been difpofed corio humano ludere, began to exprefs an anxiety, very commendable in an experimental philosopher, for the welfare of his female affiftant, and to prefs her return. This female falamander however affuring him that he felt no inconvenience from her fituation, remained there 10 minutes longer; that is near the time when Boerhaave's cat parted with her nine lives under a much lefs degree of heat; when the thermometer standing at 288 degrees, or 76 degrees above that of boiling water, the came out of the oven, her complexion indeed confiderably heightened, but her refpiration by no means quick or laborious. After M. Tillet's return to Paris, thefe experiments were repeated by Monf. Marantin, Commisfaire de Guerre at Rochefoucault, an intelligent and accurate obferver, on a second girl belonging to the oven; who remained in it without much inconvenience, under the fame degree of heat, as long as her predeceffor, and even breathed in air heated to about 325 degrees, for the space of five minutes. M. Tillet endeavoured to clear up the very apparent contrariety between these experiments and thofe made under the direction of Boerhaave, by fubjecting various animals, under different circumftances, to great degrees of heat. From his experiments, in fome of which the animals were fwaddled with clothes, and were thereby enabled to refift for a much longer time the effects of the extraordinary heat, he infers that the heat of the air received into the lungs was not, as was fuppofed by Boerhaave, the only or principal caufe of the anxiety, laborious breathing, and death, of the animals ca whom his experiments were made; but that the hot air, which had free and immediate access to every part of the furface of their bodies, penetrated the fubftance on all fides, and brought on a fever, from whence proceeded all the fymptoms: on the contrary, the girls at Rochefoucault having their bodies in great meature protected from this action by their clothes, were enabled to breath the air, thus violently heated, for a long time, without great inconvenience. In fact we should think too that the bulk of their bodies, though hot thought of much confequence by Mr. T. appears to have contributed not a little to their fecurity. In common refpiration, the blood in it's paffage through the lungs is cooled by being brought into contact with the external infpired air; In the pre Pp 2 fent have aviser fent experiments, on the contrary, the veficles and veffels of the lungs, receiving at each inspiration an air heated to 300 degrees, must have been continually cooled and refreshed, as well as the fubcutaneous veffels, by the fucceffive arrival of the whole mafs of blood contained in the interior parts of the body, whofe heat might be fuppofed, at the beginning of the experiment, not to exceed 100 degrees. Not to mention that M. Tillet's two girls may not poffibly have been fubjected to fo great a degree of heat as that indicated by the thermometer; which appears to us to have always remained on the fhovel, in contact with the hearth. It is obfervablet hat none of the animals which fuffered under Mr. Tillet's experiments exhaled any difagreeable odour: Mr. T. therefore fuppofes that the dog, from whom fo great a ftench proceeded, in the fet of experiments made by Fahrenheit, laboured under fome internal diforder, and had within him fome latent principle of corruption, which was, as it were, develloped by the extraordinary heat. If we might venture to hazard our opinion, after thofe of Dr. Boerhaave and Mr. Tillet, we should obferve, in the first place, that, among the animals used in the experiments related by Boerhaave, the dog only exhibited the phenomenon in queftion; and that in thofe of Mr. T. that animal was not employed. We fhould think therefore that the horrid ftench complained of, neither proceeded from any decompofition or putrefcency of the humours, effected by the extraordinary heat, co-operating with the vital action of the veffels (n the fluids of the animal, as is fuppofed by Boerhaave; nor that it was caused by any general or accidental vice of the humours, in the individual dog, who was the fubject of the experiment, as is fuggefted by Mr. T.; but that it may more naturally be fuppofed to arife from the fetid humour which is known to be fecreted from the glandula odorifera feated near the anus of that animal; the fecretion of which may be fuppofed to have been increased, as well as it's natural offenfivenefs greatly heightened, by the action of the heat on the living animal. Before we quit the fubject of this Memoir, we cannot, falvá confcientiâ, help interceeding with natural philofophers, în behalf of our fellow creatures of the brute creation, at whofe expence the philofophic appetite for knowledge, in matters of pure curiofity (for fuch we muft efteem the prefent) is often moft unfeelingly gratified. In the prefent inftance, though we have no material objection to Mr. Tillet's firft experiments, as we fee no great harm in an experimental philofopher's giving two willing girls afweat, in his own peculiar manner, with a view to the propagation of natural knowledge; yet we cannot think fo well of thofe which follow, nor look on our ingenious Academician as quite fo innocently employed, in putting to torture, and to death, the poor innocent rabbets, pullets and finches, |