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ART. I. Histoire de l' Academie Royale des Sciences, &c i. e. The History and Memoirs of the Royal Academy of Sciences at Paris, for the Year 1775. 4to. 1778.

ANATOMY. M EMOIR I. Concerning the Effects of Mephitic Exhalations,

V exemplified by the Death of M. LE MAIRE, and his Wife, who lived in the Street St. Honoré, at Paris, and were suffocated by the Vapour of Coal, the 3d of August, 1774. By M. Portal. The fact, that occalioned this Memoir, excited the sensibility and compassion of the Public, and drew, in a particular manner, the attention of the Medical Faculty, to an object that frequently produces pernicious, and sometimes fatal effects. A young couple, into whose apartment the vapour of coal, lighted in the hearth of a chimney, which had a communication with theirs, entered, lost their lives in one day by this unhappy accident. M. PORTAL, who was called too late to their relief, here publishes the observations which accidents of this kind have furnished him with, that speedy and well-directed succours may not be wanting to those who may hereafter be exposed to the same danger.

In those who die by the suffocation of coal-vapour, the animal beat remains for a considerable time; their members continue fexible, and the face is rather of a more lively and Aorid colour than it was in a state of health. On opening the body, there is no blood found in the pulmonary veins, nor in the vessels on the left side of the heart, while those on the right side are full of blood, and those of the brain are turgid and infated in APP. Rey. Vol. lxv, .


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a high degree. This disorder is the natural and ordinary confequence of the want of respiration, which is the cause of death in those who are suffucated by mephitic vapours, arising either from coal, or substances in fermentation. The means of relief proposed by our Academician are, phlebotomy, exposing the body to fresh and renewed air, the application of cold water, the insufflation of air into the lungs, and the use of stimulants. He insists particularly on conveying air to the lungs by a tube applied to one of the nostrils, while the other is ftopped. This latter he considers as the safest and sureft method of conveying air to the lungs, as the application of the tube to the mouth may press down the uvula, which, in such circumstances, is naturally open, and thus increase the danger. When all these means prove unfuccefsful, M. PORTAL recommends opening the arter ea trachealis, if an able surgeon can be found, who will venture upon such a critical operation, which, indeed, is the Jast resource. He looks upon the use of emetics, and the introduction of smoke of tobacco into the intestines, as dangerous; since the recovery of respiration is the great object in accidents of this nature.-The details into which M. PORTAL enters in describing the alterations observable in the bodies of suffocated persons; his enquiries into the causes from which these alterations proceed, and his manner of appreciating the different methods that may be employed for the relief of these unfortunate patients, render this Memoir highly instructive and useful.

CHEMISTRY. • Mem. I. Concerning the Nature of the PRINCIPLE which is combined with Metals during their Calcination, and which augments their Weiglt. By M. LAVOISIEK. This ingenious Academician had proved in a former memoir, that metals, during calcination, absorbed air, and that to this air they owed the real augmentation of their weight. He proved this, by shewing that a part of that portion of the atmospherical fluid, in which the calcination had been made, was absorbed ; and that the weight of the absorbed part was equal to the additional weight which the metallic calx had acquired. But as the air of the atmosphere cannot be considered as a fluid abfolutely pure, or as a simple element, it still remained a question, which of those substances that compose che atmospherical Auid it is, that is combined with metals when they pass into the state of calxes. The solution of this question is the subject of the present Memoir. As M. LAVOISIER was reducing metallic calxes by the addition of phlogiston, he perceived an expansible Auid disengaging itself from the calx, which had all the properties of fixed air ; but the same fixed air disengages itself from burning coal, to that this result did not clear up the point in question. He then bethought himself of reducing, in clofed vessels, precipitate per

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fé, or red precipitated mercury, a kind of metallic calx which is reducible without addition. From this he disengaged an aerial Auid, better adapted to animal respiration than the common air of the atmosphere, and also more capable of favouring and promoting combustion. This fluid is the same with that to which he has given the denomination of air eminently pure, which Dr. Priestley calls dephlogisticated air, and which, when mixed with nitrous air, has the property of precipitating it under the form of spirit of nitre. The process observed by our Author is largely described in this Memoir, and seems to prove evidently, that the principle which is combined with metals during their calcination, and which augments their weight, is nothing more than the purest portion of the air we breathe, which passes, in this operation, from a state of expansibility, to a state of folidity. If, therefore, it be obtained in the state of fixed air in all the metallic reductions where coal is employed, it is to the combination of the latter with the pure portion of the atmospherical air, that this effect is owing, and our Author thinks it highly probable that all the metallic calxes would, like those of mercury, yield only an air eminently adapted to respia ration, if they could be all reduced without addition, as is the care of the precipitate per fe. Our Author draws another conclusion from the above mentioned process in the following words. « Since the coal disappears entirely in the reduction or revivification of calx of mercury, and nothing is obtained from that operation but mercury and fixed air, we must conclude, that the principle to which the denomination of fixed air has been hitherto given, is the result of the combination of the eminently pure portion of the air with coal. This I design to prove and illustrate in a satisfactory manner in some subsequent memoirs on shis fubject.' .

Mem. II. New Obfervations on the Nature and faline Properties of Zinc, in a metallic Form, or reduced to a Calx. By M. De LASSONE,

Mem. III. New Details relative to the Action of volatile Ale kalies on Zinc. By the same. M. De LASSONE, in a former memoir, had made it appear, by several facts, accurately.com. pared and connected, that zinc, as well as arsenic, is poflefied of metallic and saline properties. In the two Memcirs now before us, he examines the combination of volatile alkali with zinc, both in its ftate as a metal and as a calx; and confiders the phenomena which results from this combination. The lolubility of zinc in volatile alkali was rather conjectured thaa known by the chemists. Our Academician proves, that volatile alkali, in a fluid form, diffolves the filings of zinc with effero vescence, and the flowers of zinc without effervescence, but, However, in a manner more expeditious and complete : the ala I i 2

kaline kaline liquor must be saturated and employed immediately after the volatile alkali has been procured from sal ammonjac by the intervention of fixed alkali. This new combination of zinc has given M. De LASSONE an occasion of making some enquiry into the nature of this semi metal. Some noted chemists have looked upon it as a particular combination of iron ; to which notion they were probably led by this circumstance, that iron is obtained both in mines of zinc, and from zinc prepared in the mines. M. De LASSONE endeavoured to procure Prulfian blue, by precipitating the zinc from its solution in volatile alkali, and he succeeded sometimes; but it was only when he employed in this operation either the zinc that is an object of commerce, or acids which contained a small portion of iron. The zinc that had been previously purified in his elaboratory, and the acids which had been carefully prepared, yielded no Prussian blue. Our Academician concludes from hence that zinc is totally distinct from iron, though it has some lines of resemblance to that metal, and is sometimes mixed with it.

Mem. IV. Concerning several Ammoniacal Salts. By M. DE LASSONE. The Academician examines here the combinations of volatile alkali with the acid of vinegar, with cream of tartar, with the nitrous acid, with arsenic, and with sedative salt.

Mem. V. Concerning the Reduction or Revivification of Cal es of Copper. By M. TILLET. This curious Memoit deserves the attention of the gentlemen of the mint. Theory and prace rice unite here in pointing out the least expensive method of re. ducing calx of copper in the known operation of melting it with coal.

Mem. VI. Concerning the Aetion of the ElcElrical Fluid on metallic, Calzes. By Messrs. Brisson and Cadet. Some learned philosophers, and among others, F. BECCARIA, pub. lished experiments, which proved, in their opinion, that the action of electricity reduces or revivifies metallic calxes, and chus produces the same effects that are obtained by the phlogiston of the chemists. Our Academicians have proved the contrary in this Memoir, by the justest reasonings, and repeated experiments,

Mem. VII. Obfervations on the Decomposition of fulminating Gold. By. M. Sage. It appears from the researches of Mr. Bergman, that gold acquires this fingular quality only by iis combination with volatile alkali, or (which is more probable) with one of the principles of which that alkali is composed. M: Sage describes, in this. Memoir, a singular, phenomenon, which accompanies, che detonation of fulminating gold. When iç is detonated on a plate of filver or copper, zinc or cobalt, the gold appears incrusted in the plate under a metallic form ; but on tin, lead, bismuth, antimony, and regulus of arsenic, the


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fulminating gold is no more observed under a metallic form, but under that of calx of gold, more or less deep in colour. This calx, melted with white glass, produces glass of a violet hue; but the strength of the colour varies according to the kind of metal on which the gold has detonated. If a solution of gold in aqua regia be precipitated with the metals on which the gold after detonation re-appears under a metallic form, the gold, is precipitated under the same form; but gold is precipitated under the form of a calx, by the same metals on which, after detonation, it is found without its metallic form,

· BOTANY. This class contains a Memoir by Linnæus, concerning the cyca (a kind of plant, which by its size and external form seems related to the palm tree genus, but which the Swedish Botanist places among the ferns), and a hort account given by M. Du Hamel, of a singular excrescence in the graft of an apple-tree.

ASTRONOMY. Mem. I. Oppositions of Mars, observed at Paris for several Years past, and compared with the Tabes. By M. DE LA LANDE.

Mein, 11. Elements of the Orbit of Mars, from the last Oppofitions, cal.ulated by a more simple Method than those that have been hitherto employed. By the fame.

Mem. II. Concerning the Conjunctions of Saturn with the Moon in February and March 1775 ; together with Reflexions on the Inaccuracy of the Tables. By M. LE MONNIER.

Mem. IV. Concerning the Conjunktion of the Moon with Alde. baran, observed at the Passage by the Meridian, April 1775. By the same. This conjunction may be employed to verity the greatest quantity of the moon's variation, in the mean distances between the earih and the fun.

Mem. V. Observations of Jupiter, relative to his Opposition to the Sun, December 8, 1775, mude at the Royal Observatory. By M. JEAURAT.

Mem. VI. Inquiries concerning several Points in the mundane System. By M. De La Place. The subjects created in this learned and elaborate Memoir, are, The law of gravity at the surface of homogeneous fpheroids in equilibrio.—The phenomenon of the tides, the precession of the equinoxes, and the nutation of the axis of the earth, which result from this phe. nomenon,-the oscillations of the atmosphere, occasioned by the action of the sun and the moon.

Mem. VII. Observation of the Occultation of Saturn by the Moon, made at the Royal Observatory, the 18th of February, 1775. By M. CASSINI DE THURY.

Mem. VIII, The Occultation of Saturn by the Moon, made the fame Day, in the Evening, at the Observatory of the Marine. By M. MESSIER li3


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