to be a claviculated animal, our author has difcovered this bone, but it is very imperfect: in the Guinea-pig alfo he has difcovered a bone of the fame form, and of a fimilar ftructure. In a dog we are told, incidentally, that the cefophagus is the fource of a part of the gastric liquor, and it is furnished by glands placed near the bottom of this canal: is it not the fame in man? And is not this liquor difcharged in the first efforts to vomit, when the motion of the cefophagus only is inverted? The plates not only illuftrate our author's defcription of thefe bones, but contain the neighbouring mufcles. M. Vicq d'Azyr has difcovered the clavicle alfo in the pole-cat and the weazel, which have been claffed with animals not claviculated; and he fufpects that it may be found in all animals which have divided feet.

A thunder-cloud ftruck the ftables at Ramboullet on the fecond of August, 1785. Two grooms were ftruck down, with the ufual marks on the fkin, and the ufual fymptoms of palfy. One of them had a violent pain in his head, with obfcure vifion for fome days: undoubtedly a flight effufion had taken place. Of thirty-two horfes thirty were ftruck down, but feem to have recovered without bad consequences. A heifer was ftruck dead, and another was fo much affected with a weight of the head and palfy that he died the next day. That which was killed was found to be full of extravafated air. The larger veffels were flaccid, and thofe of the head diftended with black blood almost coagulated: fimilar appearances have been found on opening men killed by lightning. The effect of it is undoubtedly to extinguish every fpark of animation, and the fluids it decompofes at leaft in part: the air feparated was probably one of the ingredients in the mixt, for there is no reafon to conclude that the fimpler elements were decompofed. One of the grooms fays only that he was knocked down, without being able to give a more diftinct account of his feelings. The horfes were particularly affected in confequence of the metalic linings of the manger.

M. le Monnier's remarks on the oppofition of the Herfchell to the fun we cannot abridge. The extract of a letter from M. André Michaux, a botanist, on his way to Ifpahan, dated Bagdat, February 23, 1783, contains fome interesting obfervations. Unfortunately his barometer was broken by the treachery of an Armenian, after he had paffed the mountains, and feemed beyond the reach of accidents. The latitude of Bagdat, from fix obfervations on the height of the fun, was found to be about 35° 15. The declination of the needle was 11° weft but, when the compafs was examined at Paris, an error of 1° 5' weft was obferved, which we do not find was accounted for. The thermometer, expofed to the north, thirty-fix feet above the Tigris, funk on the 28th of January, 1783, only to the freezing point. Perhaps we may be allowed to add, in this place, from the Journal des Sçavans, that M. Beauchamp, the aftronomical

aftronomical obferver at Bagdat, is returned from Perfia, and, though much weakened by a fever caught in Perfia, continues. his labours. In September and October laft he obferved 3000 pallages of fars, and purposes to continue his furvey of the heavens, to examine thofe ftars which have a little motion. He has fent to the Academy a catalogue of the constellation of Capricorn, compofed of fifty-one ftars, each of which has been frequently obferved: to thefe he has added eighty-nine others, but he could only determine the right afcenfions, for want of proper inftruments. A night telescope has been fent to him, to obferve comets.

M. le Monnier's account of the conjunction of the moon with the Pleiades, obferved the 13th of December, 1785, is alfo incapable of abridgment. The obfervations on the conjunction of the moon with Venus, obferved April 12, 1785, by M. le Monnier, are of the fame kind.

M. Fourcroy's remarks on the fuming oil of vitriol of Saxony, with the concrete falt drawn from it by diftillation,' are curious. It is not uncommon, in the works of the carlier chemifts, and particularly of the alchemifts, to find varieties of appearances noticed, with every mark of exaggerated defcription. Many of these authors mention an oil of vitriol, which can be procured in a concrete form, and from which a volatile concrete falt can be drawn by distillation. It is ftyled the oil of vitriol of Nordhaus; and we find that a fimilar oil has been procured from Nordhaufen in Saxony. It is ufelefs, in this place, to follow the history of this preparation, or to enlarge on what has been faid by different authors refpecting it. We shall only give an abstract of M. Fourcroy's experiments.

This acid has a powerful attraction for moisture; and its fumes, when expofed to the air, are denfe and white. After attracting moisture, though apparently denfe and oily, it weighed only one eighth more than water; but, in its purer state, it weighed nearly double. The acid reddened the blue colours of vegetables, without deftroying them. On diftilling it a concrete falt was obtained, as was faid, and it amounted to a fifth part. The fire must be gentle or the vapours form so fast that they escape at the rifings, or break the veffels, for no lute can be applied. The heat of boiling water is more than fufficient; and, when thefe white vapours have come over, the acid diftils in the ufual form. When water is mixed with this fuming acid, DO concrete falt can be drawn from it; but, when the acid is diftilled with proper precautions, light needles arife, and stick to the the neck of the retort; foon afterwards fome drops come over, which fall to the bottom of the receiver; and, in this fluid, alight brownish granulated falt concretes, fomewhat in the form of mufhrooms, fupported on fome of needle-form cryitals. The probability is, that this acid contains fome air, which, uniting with the atmospheric air, concretes, as alkaline and acid airs form a 1.1t which can no longer retain a gazeous form; or that it contains

Q2

tains a diftinct fubftance which is carried off by the fulphure ous gas, and, when it comes to atmospheric air, is depofited, entangling fome of the acid with it. The experiment will nos fucceed in finall veffels; and in mixing the acid with water a fulphureous gas efcapes, while the formation of concrete falt, as we have faid, is prevented. The last hypothesis is most probable; but we could have wished that our author had carried his experiments a little farther. These concrete falts, when rectified, preferve their form and nature in a moderate heat, and when confined in a closely corked bottle. If exposed to the air, a very thick white vapour, with the fmell of fulphureous acid, exhales, and a part of the falts melt into an oily liquor, of a clear brown, which no longer fmokes after being kept a little while in the air. They melt in water with a hifling noise, much hear, and a violent effervefcence, owing to the efcape of a ful phureous gas, and at luft they give only an oil of vitriol a little coloured.

M. Fourcroy's Memoir, fubfervient to an anatomical hiftory of the tendons, in which their mucous capfules are particularly noticed, is a very important one, and contains more inforination than many modern volumes. The mucous capfules are the burfæ mucofæe of Monro; and our author, in a very scientific history which he has given of the various labours of anatomits in this department, fhows in what refpect the names of each are applicable to the different appearances of the capfules. In his first memoir on this fubject he explains the general structure of the mucous capfules; gives the reafon of preferring this title; defcribes the internal structure and origin of these membraneous productions; gives the most effential differences, as well as the characters by which they may be diftinguished from the cellular fubstance and the sheaths of the tendons; describes the acceffory portions of the capfules; their ligamentous fupports; their filamentous ftructure, and finovial glands, as well as their general ufe. In the fecond part he gives a particular account of thofe he had difcovered, and adds fome remarks on the structure and connection of many tendons, which he thinks have eleaped former anatomists.

This extenfive outline it is impoffible for us to fill up with the flightest pretence to accuracy; and it is of fome importance that a fuller account is lefs neceffary, fince we have received fome information on the fubject from Dr. Monro. We fhall, however, notice a fact or two. From our author's defcriptions it feems as if thefe capfules were productions of the periosteum or of the proper membrane of cartilages and ligaments, though fometimes even the tendinous substance contributes to their formation. This may be particularly obferved in those which de ferve the name of burfæ, fituated at the extremity of the tendons: they do not glide on their furface, but feem on the lower fide a part of their substance, while the upper membrane is confounded with the cellular texture: and, fecondly, in the bur

fe truly capfular, which our author diftinguishes by the name of vaginal, fome confufion of fibres is obferved, and tendinous ones are intermixed, as fupporting ligaments. The liquor of thefe burfe is evidently fynovial or albuminous: it gives to water a whitish tinge, and, in hot water, coagulates: it feems to be generally furnifhed from the furfaces, but in the larger and more important capfules a glandular apparatus is confpicuous. Our author found it occafionally fubject to the fame depravations, particularly to infpiffation, and thinks that the ganglia of tendons are owing to it. These burfæ feem occafionally to communicate with the cavity of the joint. M. Fourcroy has found, he tells us, a fatty communication between the cavity of the capfule placed under the great ligament of the rozula, with the cavity of the joint of the knee. I have obferved, he adds, a communication by an aperture more than half an inch wide, between the particular capfule of the tendon of the popliteus muscle, and the external fide of the articulation of the knee, below the external condyle of the thigh, and above the posterior edge of the femilunar cartilage of the fame fide.' No one has obferved this, or remarked that the tendon of the popliteus paffes into the articulation of the knee.' There are fome flight communications between the capfules of the tendons which furround the foot, and the articular cavities of the tarfal bones; and air has paffed into the articular cavity of the fhoulder-blade, by blowing into the burfe which furround it; but the communication, mentioned by M. Janke, between the capfule of the iliac with the cotyloid cavity could not be found. We have not mentioned our author's diftinction of these burfæ from their structure; it is fufficient to obferve, that, in their form, they either proceed along the tendon, and are styled vaginal, or are fituated at the infertion of the tendon in this last form they are either placed under the tendon, and comprefied by it, or make a part of its substance, as we have already had occafion to explain. They are found more diftinctly in young than in old perfons, and, inftead of being formed by the motion of muscles, feem to be destroyed by it. They chiefly occur in the extremities, and where the tendons are long. In this memoir, however, M. Fourcroy has only examined the burfe connected with the articulation of the fhoulder-blade, humerus, and elbow: for the defcription, and the particularities difcovered in the tendons, we must refer to the work.

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The next Memoir is by the chevalier de la Marck, on the claffes that may be most conveniently eftablifhed among vegetables, and on the analogy of their number, with thofe deter mined in the animal kingdom, confidering on each fide the gra dual perfection of the organs.' We have tranfcribed this fanciful title, and the memoir is no lefs fanciful. Our author of fers fome objections to the generally-received fyftems of plants, and explains his own claffification, formerly published in his Dictionary of Botany. The great advantage of this fyftem, in

its prefent view is, that fome analogy is perceived between the different claffes, as well as the different orders of plants and those of animals. The analogy is, however, completely artificial.

M. Daubenton's comparifon of the fuperfice wool of France with the finest wool of Spain, in the fabrication of cloth, shows how far art can compenfate for natural difadvantages. We have formerly had occafion to mention our author's plan for the melioration of the wools of France. He has brought the fheep of Rouffillon to afford fuperfine wool for eighteen years, without degenerating, and a flock of Spanifh fheep for half that time without any change. In working it the manufacturer found, he tells us, that this wool had more nerve' and force than Spanish wool, with the fame fineness to the eye, and the fame foftnefs to the touch: it not only admitted of being drawn to a finer thread, but suffered a greater degree of torfion without breaking. The cloth, though manufactured in the depth of winter, had a very firm texture, and was ftronger than the cloths made with Spanish wool. In the most improved ftate, this wool was compared with the finest Spanish wool: it shrunk more in washing than the Spanish wool, a circumstance probably owing to the former having been previously forted, and more carefully wafhed; but it took an equally good dye, and fpun even to a finer thread than the imperial Leonoife'-the finet wool of Leon, and indeed of Spain. The French wool did not go fo far in making cloth, probably owing to the circumftance juft mentioned; but the cloth is faid to take an excellent glofs. The forting and washing feem to have not been conducted with fufficient care.

M. le Gendre's refearches on the indeterminate analysis we cannot abridge with any advantage. His defign is to give, first, a method of refolving, in whole numbers, the following equa

tion:

Ay=a+b-+c2+, &c.

Secondly, a method, founded on the indeterminate analysis, to difcover the divifions of numerical equations; thirdly, a theorem to judge of the poffibility or impoffibility of an indeterminate equation of the fecond degree; and, fourthly, different theorems relating to first numbers.

M. Coulumb's defcription of a new compafs, in which the needle is fufpended by filk, is wholly unintelligible without the plate. His three memoirs on maguctifm and electricity, will afford more fubjects of remark, though, as they depend fo much on his former effay on torfion, which, entangled as it was with mathematical details, fcarcely in any inftance admitting of an abstract or an abridgment, we could not properly analyfe, we fear our account will be lefs fatisfactory than we could wifh it to be. The first memoir is on the confiruction and ufe of an electrical ballance, which depends on the property of metallic threads that have a force of reaction of tortion founded on the angle of torfion. With this ballance he deter