Societies and Academies

Abstract

PARIS. Academy of Sciences, August 13.—M. Janssen, President, in the chair.—Remarks in connection with the “Connaissancedes Temps pour 1890” (212th year of publication), presented to the Academy by M. Bouquet de la Grye. Amongst the improvements and additions made to this volume are: the semi-diameter of the sun, the duration of its transit, the parallax and aberration for every day in the year, the conditions of visibility of Saturn's ring, and! tables for calculating the phases of the solar eclipses for every point on the surface of the globe. By means of certain typographical expedients, all these additions have been made without increasing the size of the volume.—On a general property of elastic solid bodies, by M. Maurice Lévy. A demonstration is offered of the following theorem: If two systems of forces in equilibrium be successively applied to an elastic solid body, whether isotropous or crystallized, free or not (and consequentlv to a system of similar bodies connected together in any way), then the sum of the work produced by the forces of one of these systems, for the elastic displacements due to, the other, is equal, to the sum of the work produced by the forces of the latter for the elastic displacements due to the first.—On the influence exercised by antipyretic substances on the quantity of glycogen contained in the muscles, by MM. R. Lépine and Porleret. In a previous note (Comples rendus for April 3, 1888), the authors-showed that antipyretic substances act as an impediment to the, transformation of the hepatic glycogen into sugar. They now give the results of their further researches on the influence exercised by the antipyrine and acetanilide in determining the proportion of glycrgen contained in the muscles. Compared with healthy animals, those intoxicated with these substances have an excess of muscular glycogen varying from 28 to 30 per cent.—On the precautions required to be taken in order to secure good photographs of lightning, by M. Ch. Moussette. An experiment is described, which is intended to show that the defective photographs of electric discharges are mainly due to the vibrations communicated to the apparatus by the trembling of the ground, the force of the wind, or the crash of the thunder. Hence, in order to obtain good impressions, these disturbing elements should be neutralized to the utmost.—Observations of Brooks's new comet, made at the Paris Observatory with the equatorial of the West Tower, by M. G. Bigour-dan. This comet was discovered by Mr. Brooks at the new Observatory of Geneva, State of New York, on August 7, 1888. It was faintly visible in Paris on August 9, and the present observations were taken on the three following days.—On amorphous antimony, by M. F. Hérard. The author has succeeded in obtaining directly the allotropic modification of antimony indicated by Gore, and resulting from the decomposition of a chloride, bromide, or iodide of antimony. It takes the form of a gray powder containing 98.7 per cent, of antimony, with density 6.22 at o° C., and point of fusion about 614°, whereas crystallized antimony melts at about 440°.—On four new titanates of zinc, by M. Lucien Lévy. Since his communication (Comptes rendus, vol. cv. p. 378) on a trititanate of zinc obtained by means of fluorides, the author has obtained four other titanates by fusing titanic acid with mixtures of zinc and potassa sulphates, These titanates are here described, analvzed, and reduced to their proper formulas.—M. A. Duponchel has a note on a 24-years' cycle of periodicity in the oscillations of temperature on the surface of the globe, based on the records of mean temperatures in Paris from the year 1765 to 1783, and from 1804 to the present time.