Societies and Academies

Abstract

PARIS. Academy of Sciences, September 10.—M. Des Cloizeaux in the chair.—Remark on a point in the theory of secular irregularities, by M. F. Tisserand. The reference is to Le Verrier's statement regarding the stability of the planetary system, in connection with a certain position between Jupiter and the sun, determined at about double the distance of the earth from the sun. An attempt is made to ascertain whether there exists an analogous position, in which the originally slight eccentricity of the orbit of a small mass might gradually assume proportions calculated to disturb the general equilibrium of the system.—The French vines, by M. A. Chatin. The treatment is described, by which a vineyard at Meyzieux, Isère, has been preserved, like a green oasis, in the midst of the wilderness created round about by the combined attacks of Phylloxera, mildew, and black rot. The treatment consists partly in a systematic process of nippings (éborgnements), partly in the application of a strong manure, including granulated phosphorus and products, with a base of nitrogen, potassa, and lime.—Degrees of oxidation in the fluorescent compounds of chromium and. manganese (continued), by M. Lecoq de Boisbaudran. Several experiments are described tending to show that the pink compound is the real cause of the fluorescence.—Observations of Barnard's new comet, made at the Paris Observatory (equatorial of the West Tower), by M. G. Bigourdan. This comet, discovered on September 2 at the Lick Observatory, showed on September 5 a round nebulosity from 1′ to 1′.5 in diameter, with somewhat stellar nucleus of 11.5–12 magnitude, not occupying the centre of the nebulosity.—Positions of Brooks's comet (August 7, 1888), measured at the Observatory of Beson, by M. Gruey. The observations are for August 9–12, when the magnitude varied from 7 to 9.—On the planet Mars, by M. Perrotin. These remarks are made in connection with four new designs of Mars, forming a sequel to those published in the Comptes rendus of July 16. They still show the two canals—one simple, one double—running from the equatorial region nearly along the meridian towards the North Pole. A new canal is also revealed, which presents the appearance of a straight dark band traversing the white Polar ice-cap.—On the chlorides of indium, by MM. L. F. Nilson and Otto Pettersson. To the previously-determined trichloride, InCl3 the authors here add three distinct and stable chlorides. These are a trichloride, InCl3, a dichloride, InCl2, and a monochloride, InCl, showing that a metal of the third group in the natural system of the elements may act as a mono-, a di-, and a tri-valent in clearly-defined combinations.—On the part played by symbiosis in certain luminous marine animals, by M. Raphaël Dubois. In previous communications the authors showed that the fundamental reaction necessary to produce animal luminosity was of the same order as those effected under the action of the ferments. Their further studies of Bacillus pholas and Bacterium pelagia, the respective parasites of Pholas dactylus and Pelagia noctiluca, enable them to reconcile their theory of photogenous fermentation with the hypothesis of the oxidation of a phosphorated substance, as proposed by some biologists. These researches also help to explain how marine phosphorescence may be caused by the disintegration of marine animals, and how this phenomenon may cease or reappear, and assume various degrees of intensity, according to circumstances.—On the myelocytes of the Invertebrates, by M. Joannes Chatin. Hitherto spoken of as present in the organism of the Vertebrates alone, the author here shows that the myelocyte formation occurs also in the Invertebrates. He makes it evident that they cannot be assimilated to free nuclei, but represent true cellules normally constructed, with all their essential parts. He further points out that the intimate structure and real nature of the myelocytes may be studied much more conveniently in the lower than in the higher organisms.—On Heterodera schachtii, by M. Willot. In connection with his recent communication (Comptes rendus, August 3), on the destruction of this micro-organism by sea-water, the author points out that Dr. Strubell, of the University of Erlangen, has independently, but subsequently, made the same discovery.