Societies and Academies

Abstract

PARIS. Academy of Sciences, September 30.—M. Bouquet de Grye in the chair.—The problem of the dissipation of heat in thick wall with radiating surface, by M. J. Boussinesq.—Remarks on the formation of acids in plants, by MM. Berthelot and Andre. It has been found, that there is no relation between the total amount of vegetable acids contained in a plant, in the free or combined state, and the amount of acid in the juice extracted from the various parts.—On the engraved and painted figures of the Pakolithic period found on the walls of the cave of La Mouthe (Dordogne), by M. Emile Riviere. A minute description of prehistoric drawings, the existence of which was first indicated in 1895 The cave is nearly filled up with débris of prehistoric man, who inhabited the cave at two distinct epochs, which are clearly distinguished by a stalagmitic layer which separates them. The drawings are of three kinds, simple line engravings, others filled with a brownish-red ochre, and third a kind of striation of the rock. All, with one exception, represent animals, the most perfect being complete figures of bison and of a kind oi antelope. The wild goat and reindeer are also recognisable.—On differential equations of the second order with algebraical coefficients, by M. Paul J. Suchar.—On the variable stte of currents, by M. A. Petot.—The calculation of the heat of volatilisation and heat of fusion of some elements, by M. de Forcrand. The relation (L + S)/T = (l+s)/T = 30 between the molecular weight M, the heat of fusion 5, the heats of volatiljsation and fusion L, I, and the temperature, is applied to the cases of phosphorus, arsenic and selenium.—Nitromannite and nitrocellulose, by MM. Leo Vignon and F. Germ. It has been previously shown by one of the authors that the various nitro-derivatives of cellulose energetically reduce an alkaline copper solution. It is now shown that penta- and hexa-nitromannite behave similarly. This reducing power is not altogether due to the formation of mannose. Nitromannite, reduced by ferrous chloride, gives a mannite devoid of reducing power. From this point of view it behaves differently from the nitro-celluloses.—The formation of an isatiri derivative of albumen, by M. Julius Gnezda. A substance giving the reactions of chlorisatin has been obtained from the products of the reaction between hypochlorous acid and peptone.—On the reproduction and development of Peripatopsis Blainvillei, by M. E. L. Bouvier.—On stolonisation in the hydroides, by M. Armand Billard.—The fibrovascular elements of the stem and frond of some Filicineacæ, by MM. C. Eg. Bertrand and F. Cornaille.—On the localisation and dissemination of antimony in the organism, by M. G. Pouchet. The toxic action of antimony and its localisation require doses of antimony much larger than with arsenic, the loalisation of antimony being different from that of arsenic. The toxic action of arsenic is not diminished by the presence of antimony, but, on the contrary, appears to be somewhat increased.