Abstract
PARIS Academy of Sciences, August 2.—M. Edm. Becquerel in the chair.—The following papers were read:—On the preparation of chlorine, by M. Berthelot. The formation of the brown soluble compound (preceding the liberation of chlorine) requires not only chlorine and manganese, but a considerable excess of hydrochloric acid; it is a perchlorised chlorhydrate of manganese.—On heats of combustion, by M. Berthelot. This relates to the agreement between Thomsen's results and his own.—Synthesis of hexamethyl benzine and of mellic acid, by MM. Friedel and Crafts.—On human walking, by M. Marey. With his odograph he proves that the step is longer in mounting than in descending for an unburdened man than for one carrying a load, for one with very low-heeled, than for one with high-heeled shoes, for one with a thick sole prolonged slightly beyond the foot than when the sole is short and flexible. It seems as though the heel might be lowered indefinitely with advantage, but soles must not be elongated beyond a certain limit, nor made quite rigid. Sometimes (as in ascending) the length of the step is increased, and the rhythm retarded; at other times (as in more rapid walking) the step both lengthens and is accelerated.—Report on the interoceanic canal project. (Second Part.) M. de Lesseps documents are approved.—On the gallicolar phylloxera and Phylloxera vastatrix by M. Laliman.—M. Zazareff described a battery in which electricity is produced by passage of a solution of glycerine, under pressure, through a mixture of coke and anthracite.—On the theory of sines of superior orders, by M. Farkas.—Researches on the electric effluvium (silent discharge), by MM. Hautefeuille and Chappuis. M. Thenard's apparatus (with alternative discharges) is well fitted to show the rain of electric fire in various gases. Fluoride of silicium gives the best effects; nitrogen comes next; hydrogen and chlorine also present the phenomenon.—Researches on batteries, by M. D'Arsottval. He indicates two methods of obviating the chemical action which goes on in batteries with two liquids when the circuit is open. The first consists in use of animal charcoal, substituted e.g for the sand in a Minotto battery; the second, in using, as a depolariser, a liquid which gives a precipitate by its mixture with the liquid which attacks the zinc (there are many ways of doing this; and the author mentions some). In the latter case the diaphragm is rendered impermeable by means of a conducting and electrolysable precipitate.—On the optical properties of mixtures of isomorphous salts, by M. Dufet. Let N be the index of the mixed salt, n and n′ those of the components, p and pf the numbers of equivalents of the two salts; then N=pn+p′n′/p+p′ This law is demonstrated, at least, for sulphates of the magnesian series.—Influence of temperature on the distribution of salts in their solutions, by M. Soret. The concentration of the beated part diminishes, that of the cold increases. The difference grows with the original concentration, and nearly in proportion. In the series of the alkaline chlorides the difference is greater (for the same concentration), the higher the molecular weight of the salt. The phenomenon seems to have no relation to solubility of the salt.—On the rise of the zero point in mercury thermometers, by M. Crafts. This rise (through heating) is quicker and greater in crystal thermometers than in those of glass without oxide of lead; it is quicker at first, and tends to a limit (with heating at fixed temperature). The zero point becomes fixed at the new height, when the instrument is kept at ordinary temperature and the thermometer becomes more stable.—Development, by pressure, of polar electricity, in hemihedrai crystals with inclined faces, by MM. Jacques and Curie.—On the pyridic bases, by M. de Coninck.—On the heats of combustion of some substances of the fat-series, by M. Louguinine.—Identity of acute experimental septicæmia with the cholera of fowls, by M. Tous-saint.—Formation of new races; researches in comparative osteology, on a race of domestic oxen observed in Senegambia, by M. de Rochebrune. The animal—a zebu—is specially distinguished by a conical nasal horn—Action of poison on cephalopoda, by M. Yung. The effects of curare, strychnine, nicotine, &c., are described.—On a hailstorm at Paris on July 30, 1880, by M. Ferrière.—On determination of crystallisable sugar in presence of glucose and dextrine, by M. Pellet,
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Societies and Academies . Nature 22, 356 (1880). https://doi.org/10.1038/022356a0
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DOI: https://doi.org/10.1038/022356a0