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PARIS. Academy of Sciences, April 10.—M. Emile Bertin in the chair.—E. Borel: Arithmetical definition of a distribution of masses extending to infinity and quasi-periodic, with average density zero.—I. Fred-holm: An application of the theory of integral equations.—J. Andrade: The mechanical problems of regulating springs.—P. Vuillemin: A new species of Syncephalastrum: the affinities of this genus.— E. Vessiot: The conformal geometry of systems of circles.—M. Janet: The invariant canonical forms of algebraical and differential systems:-T. Carleman: Demonstration of a theorem of M. Borel.—A. Myller: Remarks on M. Carleman's note.—A. Myller: Some properties of ruled surfaces in connection with the theory of parallelism of M. Levi-Civita.—H. Chretien and P. Ditisheim: An electrochronograph recording the time, in figures, to hundredths of a second.—M. Sauger: A remarkable coincidence in the theory of relativity.—MM. Berloty and Combier: The eclipse of the sun of March 28, 1922, observed at the Observatory of Ksara (Syria).—I. Tarazona: Observation of the annular eclipse of the sun of March 27-28, 1922, made at the astronomical Observatory of Valencia (Spain).—J. Guillaume: Observations of the sun made at the Lyons Observatory during the fourth quarter of 1921. Observations were possible on 76 days diiring the quarter. The results are given in three tables showing the number of spots, their distribution in latitude, and the distribution of the faculse in latitude.—H. Chaumat: An arrangement permitting the elimination and determination of the correction factor of wattmeters. —C. Dévé: The noise caused by aeroplanes. The pitch of the sound heard as an aeroplane is passing overhead varies according to the distance of the observer's ear from the ground, rising about two octaves when the ear is lowered to about eight inches from the soil. Possible causes of this phenomenon are discussed.—J. Galibourg and F. Ryziger: A method of recognising cultivated Japanese pearls. The hole usually drilled in the pearl for attaching to an ornament is utilised. A mirror is formed by placing a minute drop of mercury in this hole, the pearl is illuminated from the side and the structure examined microscopically. Differences between the natural and cultivated pearl are brought out in this way, and reproductions of photographs illustrating the differences observed are given.—P. M. Monval: The preparation of ammonium chloride. Determinations of the solubilities in saturated solution of sodium chloride, sodium carbonate, ammonium chloride, and ammonium carbonate, singly and in combination, the results being summarised on a Le Chatelier square diagram.—P. Riou: The velocity of absorption of carbon dioxide by alkaline solutions. A contribution to the experimental study of the ammonia-soda process.—C. Chéneveau: An application of the optical method of determination of the solubility of one liquid in another.—R. Fosse and A. Hieulle: The tendency of formaldehyde to form hydrocyanic acid by oxidation in an ammoniacal silver solution. Formaldehyde was oxidised in strongly ammoniacal solutions containing ammonium chloride and silver nitrate by a large excess of potassium permanganate. Working with 10 milligrams of formaldehyde in each experiment, a yield of 30-36 per cent, of hydrocyanic acid was obtained. —A. Lanquine: The direction and dislocations of the Cheiron strata to the south of the upper Estéron, up to the high valley of Loup (Maritime Alps).— A. Guébbard: Remarks on the last Provenjal earth-quake.—P. Garrigou-Lagrange: Great movements of the atmosphere and weather prediction.—E. Gain: The ultra-maximum temperature supported by the embryos of Helianthus annuus. If the seeds are gradually dried and heated by stages, with interposed periods of cooling, the seed can survive exposure to much higher temperatures than has been hitherto supposed. One lot of seeds submitted to this treatment gave 80 per cent, germination after a final exposure to 145° C., but this result was exceptional; another lot of seeds gave only 2-5 per cent, of germinations after the same exposure.—A. Petit: Concerning the “awakening” of arable earth. In a recent paper A.' Lumiere has pointed out the favourable effect on soil of a thorough washing with water. This washing acts as though it removed products opposed to the germination of seeds. The author directs attention to the fact that he published similar observations in 1909.—W. Kopaczewski: The differentiation of phenomena of shock by contact.— R. Bayeux: Maximum respiration at very high altitudes. An account of experiments on two subjects at Chamonix (1050 metres), the Vallot Observatory on Mont Blanc (4370 metres), and at intermediate heights.—W. Koskowski: Nicotine and the inhibitory nerves of the heart. Nicotine does not act on the heart by the intermediary of the pneumogastric nerve, but directly on the intracardiac ganglia.—J. Mawas: The lymphoid tissue of the spiral valve of the middle intestine of Ammocœtes branchialis and its morphological significance.— A. Dehorne: The muscular histolysis and phagocytosis in the coelom of the Nereids at sexual maturity. —K. Abrest: The toxic index of illuminating apparatus, of heating apparatus, and of explosion motors. The ratio of carbon monoxide to carbon dioxide produced in any form of lighting or heating apparatus is termed the toxic index. This magnitude has been estimated for various forms of lighting burners and radiators, and in the exhaust of explosion motors.
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Societies and Academies. Nature 109, 631–632 (1922). https://doi.org/10.1038/109631a0
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DOI: https://doi.org/10.1038/109631a0