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Societies and Academies

Nature volume 71, pages 287288 (19 January 1905) | Download Citation

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PARIS. Academy of Sciences, January 9.—M. Troost in the chair.—The external or superficial conductivity representing for a given body the cooling power of a fluid current: J. Boussinesq.—The micrographical study of the meteorite of the Diablo Canyon: H. Moissan and F. Osmond. The micrographical study of this meteorite has shown that the metallic parts, apparently homogeneous, frequently contain irregular microscopic nuclei formed of superposed layers of phosphide and carbide of iron. A detailed examination of nodules which have not been submitted to external oxidation made it clear that they are formed of sulphide of iron surrounded by successive layers of iron phosphide and carbide. In certain cases the laminated structure of the nodules showed that they had been submitted to very considerable pressures.—Trypanosomiasis and the tsetse-fly in French Guinea: A. Laveran. Specimens of Glossina, or the tsetse-fly, have been found in all parts of French Guinea, and in places where the existence of diseases due to trypanosomes has been already demonstrated. These trypanosomes attack horses as well as human beings, and a detailed account of the course of the disease in a horse, together with the results of a post-mortem examination of the animal, are given.— Observations on the Borrelly comet (December 28, 1904) made with the large equatorial at the Observatory of Bordeaux: G. Rayet. Two sets of observations were made on December 31, 1904, and one on January 2. On the latter evening the sky was clear, and the comet appeared as a nearly round nebulosity of about 1′ in diameter, possessing a stellar nucleus of the thirteenth magnitude.—On a method of reading large surfaces of mercury: A. Berget. A collimator with a well illuminated very narrow slit is placed behind the column to be read, and an ungraduated thermometer tube in front. A luminous line, the focal line of a cylindrical mirror, is formed, and ends with great sharpness at a fixed point, which can be read off in a cathetometer with an accuracy of 0.01 mm.— The attraction observed between liquid drops suspended in a liquid of the same density: V. Cremieu. Drops of olive oil, suspended in a mixture of alcohol and water of as nearly as possible the same density as the oil, ascend or descend in a vertical straight line, with extreme slowness, if precautions against changes of temperature and shaking are taken. If two or more drops are present in the dilute alcohol at the same time, there is an attraction between the two drops which is manifested by their following curved paths instead of vertically straight ones.—On the photogenic radio-active properties of calcined coral placed in a radiant vacuum and submitted to the influence of the kathode rays: Gaston Séguy. Amongst various substances examined calcined coral (carbonate of lime and magnesia) gave the most intense phosphorescence as measured by the action on a photographic plate. Phosphorescent coral excites the fluorescence of barium platinocyanide screens, and is very rich in ultra-violet rays.— Concerning the action of very low temperatures on the phosphorescence of certain sulphides: F. P. Le Roux. The maximum potential light energy which can be induced in a given phosphorescent body by a given light is independent of the temperature. Variations of temperature can only have an influence on the velocity of transformation of the potential into the actual light energy.—On a supposed demonstration of the existence of the n-rays by photographic methods: M. Chanoi and M. Perrigot. The authors have repeated an experiment of M. Bordier's on the photographic detection of the n-rays emitted by tempered steel, with contrary results. They find that two equal masses of lead and tempered steel, placed identically on screens comparable as to thickness and insolation, never give different halos, whatever may be the duration of the exposure.—The special sensibility of the physiological ear for certain vowels: M. Marage.—On the fluorides of indium and rubidium: C. Chabrié and A. Bouchonnet. The fluoride of indium was prepared by dissolving the hydroxide of the metal in hydrofluoric acid, and was found on analysis to possess the composition In2F6.18H2O. It emits acid vapours, and is completely decomposed on ignition to redness. On treating rubidium carbonate with hydrofluoric acid and evaporating to dryness the acid fluoride RbF. HF is obtained.—The limit of the reaction between diazobenzene and aniline: Léo Vigrnon. Aminoazobenzene does not react with diazobenzene either in aqueous or alcoholic solution. Aniline reacts with diazoaminoazobenzene chloride in presence of potassium carbonate giving a diazoamine.—Camphene, camphenylone, isoborneol, and camphor: L. Bouveault and G. Blanc. The tertiary alcohol, methylcamphenylol, was prepared from camphenylone by Grignard's reaction. The reaction of this alcohol with pyruvic acid at 140°–150° C. has been studied.—On the diastatic coagulation of starch: J. Wolff and A. Fernbach.—The estimation of carbon monoxide in confined atmospheres: Albert Lévy and A. Pécoul. The authors utilise the reaction first indicated by M. Gautier between carbon monoxide and iodic anhydride at 80° C, modifying the method by receiving the vapours of iodine in a small quantity of pure chloroform. The amount of iodine set free is ascertained calorimetrically by comparison with a set of sealed tubes containing known quantities of iodine. It is possible in this way to measure in four litres of air only down to 1/200,000 of carbon monoxide by volume. A test analysis with an artificially prepared atmosphere is given to show the accuracy of the method.—On the rational estimation of gluten in wheaten flour: E. Fleurent. It is shown that by taking certain precautions as to the temperature and lime contents of the wash water, and fixing the time of washing, it is possible to obtain results by the mechanical method which agree well with the chemical method.—Physicochemical researches on hæmolysis: Victor Henri.—The comet e 1904, discovered December 28, 1904, at the Observatory of Marseilles: M. Borrelly.—The provisional elements of the new Borrelly comet (1904 December 28): G. Fayet and E. Maubant.—On the isochronism of the pendulum in the astronomical clock: Ch. Féry. For an amplitude between 2° 13′ and 2° 29′, that is, for a variation of amplitude of about 9 mm., the variation of the rate was nil, or there was a minimum for the time of oscillation. This result is probably due to a want of isochronism of the escapement.—On the value of the magnetic elements on January 1: Th. Moureaux.—Osmotic communication in fishes between the internal and external media: Jean Gautrelet. Referring to a recent paper by M. Quinton, the author directs attention to a paper of his bearing on the same subject published in 1902.–On the infection of Padda oryzivora by Trypanosoma paddae and by Halteri-diuni Danilewskyi: M. Thiroux.

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https://doi.org/10.1038/071287a0

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