and fo on to accumulated inftances of abfurdity.-This is, indeed, the fhameful part of the work before us, of which we may fay in the words of Horace:

turpiter atrum Definit in pifcem mulier formofa fuperne

Is it not, in effect, moft deplorable and difgufting, to see above an hundred and twenty pages of the most hideous nonfenfe about tranfubftantiation, at the conclufion of a book, in which we find order, method, an agreeable manner of treating abstract and speculative subjects, warmth of style and expreffion, and a very confiderable acquaintance with ancient and modern philofophy? No mortal would think, that the concluding fection of this treatise on matter, which confiders the connexion between metaphyfical Science and natural philofophy, could come from the fame pen, that was defiling the philofophic page, fome moments before, with the filthy jargon of fcholaftic theology. This laft fection would be a very proper introduction to a course of natural philofophy; it is fhort, judicious, and steers a middle way between the vicious method of interpreting nature by hypothetical speculation, and the equally defective one, interrogating her by infulated and unconnected experiments, that neither lead us to the knowledge of her plan, her Author, nor her end.

[ocr errors]


Hiftoire de l'Academie Royale des Sciences, &c-i. c. The Hiftory and Memoirs of the Royal Academy of Sciences at Paris for the Year 1773. 4to. 1777.


Memoir. On the Variations of the Magnet in the Years 1772 and 1773. By M. LE MONNIER.

WE by M. LE MONNIER to diminish the error oc

E find, in this Memoir, an account of the methods


cafioned by friction, in the experiments on the direction of the magnetic needle, more efpecially in variation compaffes. In what manner foever a needle is fufpended, the refiftance of the friction prevents its taking exactly the direction which it would have followed, had it played at liberty. This refiftance increases in proportion to the weight of the needle, as does also the magnetic power, according to the obfervation of our acade mician; and from hence he concludes, that the most perfect needle is not that which is attended with the smallest degree of friction, but that in which the refiftance, arifing from friction, will be in the leaft proportion with the directing power. He thinks, it would be proper to augment the magnetic power of the needle by increafing its weight; even though this might render the refiftance of the friction proportionably greater; be


caufe it might be poffible to correct the error arifing from hence, or at leaft, to make a proper eftimate of it. The error might be corrected by following the mean between two obfervations that would yield, the one a direction tending too much towards the east, and the other, a direction too much to the weft; and it might be eftimated by experiments well calculated, and repeated for each dimenfion, and each degree of weight which it might be thought proper to give to the needle.

The difference, which is obferved between the directions, indicated by the compaffes, in places that are little distant from each other, while at greater diftances the directions are the fame, form, in the judgment of M. LE MONNIER, a strong proof of the neceffity of perfecting ftill farther the conftruction of the compafs, and of fixing exactly the true magnetic meridian.

M. MONNIER, after feveral judicious obfervations on the improvement of this useful inftrument, gives an account of the experiments he made with two different compaffes, carefully placed, one at the Temple, and the other on the terrass of the Thuilleries. To avoid all error proceeding from diurnal variations, he made his obfervations every day at the fame hour. The magnetic needle pointed to Paris, on the fide of the eaft, in the beginning of the last century; it continued to return toward the north until the year 1666, and after that period, it paffed over to the fide of the weft. It remained afterwards ftationary for fome years, and M. LE MONNIER thinks, he may venture to affirm, that it was fo ftill, in 1773. Obfervations on the Tides at Madagascar, in the Torrid Zone, By M. LE GENTIL.

Memoir. Concerning the Form of the Bar or Metallic Canductors, defigned to preferve Buildings from the Effects of Lightning, by conveying it into the Earth. By M. LE ROY.

One of the most extraordinary things we meet with in this memoir, is the obftinacy with which the French have rejected the ufe of metallic conductors, notwithstanding the experimental demonftrations, fo often repeated, of their falutary effects. M. LE Roy laments it as a juft reproach caft upon his nation, "that it adopts with eagerness the frivolous modes of its neighbours," (he meant, we fuppofe, invents frivolous modes for itself, which its neighbours are foolish enough to imitate)" while useful difcoveries, whofe advantages are afcertained by reafon and experience, are fcarcely ever employed by his countrymen, before they have been adopted by all the reft of Europe.'

The fubject of this memoir is the form which ought to be given to metallic conductors. This point was controverted in England a few years ago. Some gave the preference to thofe conductors which rife but a little above the building on which they are fixed, and whofe extremity is blunt and obtufe: others,


following the opinion of Dr: Franklin, maintained the fuperior merit and efficacy of those which were more elevated, and pointed: this opinion was followed in the conductors fixed on the powder-magazines at Purfleet: and the memoir now before us, contains a confiderable number of experiments, that confirm it in the strongest manner. The refult of these experi ments may be contained in the following propofitions: -That it is erroneously afferted, that the painted conductors draw the lightning fooner from the clouds, than those whose extremities are blunt, obtufe, and prefent a fort of a round knob-for the contrary happens in fact: that this error arifes from confounding the property of filently drawing fire from the clouds, with that of exciting lightning, two things which are very different, as M. Le Roy abundantly proves, in this memoir :-that the conductors being defigned, by their form, to draw the fulminating matter from all the parts of the building on which they are erected, ought, for that reafon, to be pointed, and to be Faised to a certain height above the building :-and that, finally, fhould an explosion of lightning fall upon these conductors, its effects would be much lefs violent, than if it fell upon the others.


MEMOIR I. Obfervations on the Situation of the Liver, in its natural State, together with Remarks on the Manner of per

ceiving feveral of its Disorders by the Touch. By M.


[ocr errors]

In order to acquire, by the touch, a certain knowledge of the diforders of the liver, it is neceflary to afcertain, by a series of obfervations, its fituation, which differs according to the age and attitudes of the patient, and which is alfo modified by feveral maladies, which do not immediately affect the gland itself. The liver is larger in the fœtus than in children newly born. The ftomach of the former, which was perpendicular, becomes gradually almoft horizontal: the left lobe of the liver, when deprived of the blood, which was conveyed thither by the umbilical vein, diminishes confiderably in fize: M. Portal obferves farther, that this is not the only change occafioned by the revolution, which takes place in the circulation of the blood at the period of birth: the pelvis affumes gradually another form, the lower extremities, which receive a greater quantity of blood, grow in length, and acquire a new degree of ftrength and confistence. The form of the bafon in the foetus, and the fmallness of the lower extremities, are favourable to delivery: the child in the first period of life, when its weakness will allow it nothing beyond a kind of reptile motion, is fo conftituted, as to go on hands and feet; but as foon as the legs acquire trength, fufficient to fupport the body in an erect posture, their


proportion, and that of the thighs change; and all these changes, which are the neceffary confequences of a change of circulation, feem evidently to have been prepared and combined by the Author of Nature for the advantage of the human frame.

[ocr errors]

The growth of the liver is not proportionable to that of the other parts of the body. In perfons who have arrived at a mature age, it lies entirely concealed under the fpurious or baftard ribs, when they are placed in a horizontal fituation. When they are in a different or erect pofition, the liver becomes perceivable, and this is therefore the fituation that must be preferred, as the most adapted to exhibit, to the touch, the true ftate of that gland.

The liver acquires a monftrous volume by the exceffive use of food, as appears from the experiments that have been made on animals. Stoppages, or obftructions in the lungs, change the fituation of the liver, which, in thefe circumftances, extends itself under the ribs; but we muft not, according to Mr. Portal, conclude from hence, that the liver is attacked: this is an error, into which he acknowledges that he has fometimes fallen, but the diffection of bodies undeceived him.

The liver, fays our Author, is not the only part of the body that changes its fituation in different attitudes. M. PORTAL obferves, that the anterior part of the bladder, in a man who ftands upright, correfponds with the fame parts of the abdomen, to which the bottom of the bladder correfponds in a man who lies in a horizontal pofture. This remark may be of confiderable ufe and importance in medical practice. Such is the refult of M. PORTAL's memoir, to which we refer the Reader. for farther details and illuftrations, relative to this interefting object of anatomical inveftigation, which he will find here very amply and accurately defcribed and confidered. MEMOIR II. Concerning an extraordinary Pregnancy. By M. HALLER.

This memoir contains the hiftory of a woman, who, after having discovered all the fymptoms of pregnancy, which the reckoned from the beginning of the month of June 1763, fell into a state of infirmity and languor, in which all these fymptoms totally disappeared. She recovered her health in the month of May 1764: and the exhibited no marks of weakness or indifpofition until July 1772.-She died in Auguft, that year, after a violent fever, which lafted feven days, and was accompanied with intenfe pains. On opening the body, a kind of fack or tumour was found, which communicated with the uterus by the ilium on the right, and a part of the os facrum. This fack, which had within it the right tube and ovaria, contained a foetus of feven months, whofe putrefaction had occafioned the death of the woman; however, the circumftantial


account which is here given of her diforder and pregnancy, proves evidently, that the foetus had been without life from the month of January 1764. Notwithstanding this, the woman enjoyed a perfect ftate of health during eight years, with this lifeless mafs in her body, and barrennels feemed to be the only effect it produced in the animal economy. M. HALLER mentions it as a circumftance worthy of notice, that after having fuffered pains that feemed to indicate a miscarriage, in January 1764, which may be confidered as the time of the death of the foetus; the woman fuffered again pains of a like nature, at the period which, according to the proper calculations, would have brought on the delivery; he obferves farther, that at this period fhe had milk, which was, indeed, foon diffipated, but returned two months after.

MEMOIR III. Concerning a new Method of performing the Am putation of the Extremities. By M. PORTAL.

This memoir is defigned to prevent the inconveniencies that arife frequently from the ordinary method of amputation, after which a part of the bone ftill remains jutting out. This not only renders often a new operation neceffary, but also makes the cure difficult, expofes to dangerous accidents, and even after the cure is finished, prevents the ftump from being covered with flesh, which is attended with feveral difagreeable circumftances. We fhall not enter into a particular analyfis of this memoir, which might be obfcure without the affiftance of the cuts that accompany it. We fhall only mention the fact upon which M. PORTAL founds his new method, and fhew, in a few words, in what this method effentially confifts. The fact is, that the foft parts of the human body are almost all fufceptible of contraction, after being cut; and this, though in a smaller degree, is obfervable, even in dead bodies. This contraction, or rather contractibility, is different in different parts of the human frame: it is ftrong and intenfe in the fkin, the adipofe membrane, the tendons, the aponeurofes of muscles, in the veins and arteries; and its moft powerful effect is produced in the moment of the feparation of the parts, though even after this feparation, it remains in activity for a confiderable time. It muft, confequently, happen after the amputation of a member, that the foft parts, fhrinking in, leave the bone uncovered; and that the different parts, fuffering a greater or lefs contraction, the wound affumes a pyramidal form, which renders the dreffing more embarraffing, and the cicatrization more difficult.

If therefore (to come to what M. PORTAL propofes) the muscle be cut in the moment of its greatest contraction, it will fhrink lefs than if the amputation had been made at the time of its greatest dilatation or extenfion, and a more confiderable part


« VorigeDoorgaan »