Abstract
PARIS. Academy of Sciences, July 23.—M. Albin Haller in the chair.—H. Deslandres: Mountain observatories. A description of the heights, position, and equipment of the existing mountain observatories. The four iVmerican observatories (Lick, Arequipa, Flagstaff, Mount Wilson) can be occupied all the year round, are equipped with large instruments, and have already produced important results: of the others, those on Mont Blanc, Pic du Midi, and Etna are insufficiently equipped and observations can be made only for a short period of the year. For a new French observatory Revard (near Aix-les-Bains) and Fort Romeu (Pyrenees), altitudes 1500 metres and 1800 metres respectively, have been examined. Fort-Romeu possesses the advantages of possible occupation all the year round and ease of access.—G. Bigourdan: The use of a completely free pendulum as a chronometer.—F. E. Fournier. The forms of hull most favourable to high speeds are only realised in racing automobiles.—de Seguier. Linear groups with bilinear or quadratic invariant in the real and complex field.—S. Sanielevici. An application of the tensorial calculus.—Evans. Poisson's integral.—F. H. van den Durgen: Some technical applications of integral equations.—Emile Belot: An attempt at the representation of the period of continuous evolution, /, of the stars as a function of the effective temperature, 0. Application to the sun.—R. Jarry-Desloges: The influence of the various elements of an objective (aperture, focal distance, magnification) on the quality of telescopic images. Diaphragms smaller than two-thirds of the diameter of the objective cannot be usefully employed. As regards magnification there exists an optimum focal length of the refractors, between 6 and 675 metres: this result is new and difficult to explain.—E. Selety: The possibility of an infinite potential, and of a mean velocity of all stars equal to that of light.—Wladimir de Belaevsky: A problem of elasticity in polar co-ordinates.—Th. De Donder: Synthesis of the gravific.—Camille Gillet: Aqueous solutions. The origin of osmotic effects. Starting with the assumption that water is a mixture in equilibrium of hydrol (H2O), dihydrol (H2O)2 and of polyhydrol (H2O)n, of which the first is gaseous, a theory is developed affording an explanation of the existence of osmotic pressure, nocculation of solutions and of sols by electrolytes, the nocculation of sols by other sols, and the formation of emulsions.—A. Boutiric and M. Vuillaume: Study of the absorption spectrum of sols of arsenic sulphide.—Alfred Gillet: Researches on electrodiffusion (migration of the ions). Experiments on the migration of the ions in jellies (gelatine) containing sodium sulphate. A. Lassieur: The electrolytic estimation of antimony. If a thin coating of mercury is deposited on the cathode, and the potential not allowed to go over 1.3 volts, the antimony subsequently deposited electrolytically is coherent and accurately corresponds with the weight of metal present.—L. J. Simon: The sulphochromic oxidation of the aromatic hydrocarbons and the present conception of graphite. Comparison of the oxidation of aromatic hydrocarbons by sulphuric acid with chromic acid and silver bichromate, together with the results of the application of the silver bichromate reagent to various forms of carbon and coal.—L. S. Glichitch: The estimation of easily dehydrated alcohols in essential oils. The estimation of free alcohols in essential oils by acetylation fails in the case of certain alcohols, water being removed and hydrocarbons formed. By replacing acetic anhydride by a mixture of this substance with formic acid, this difficulty is overcome.—J. Orcel: The bavalite of Bas-Vallon.—Thiebaud: Researches on the mineralogical composition of some chalk marls of the Tertiary of Alsace.—A. Cholley: Evolution of the karstic relief of the Parmelan (Prealpes de Savoie).— Henri Coupin: The supposed formation of chlorophyll in the dark. Experiments are described contradicting the view that etiolated plants can manufacture chlorophyll in the dark.—Jean Politis: The formation of a glucoside (saponarine) in the mitochondria.—A. Demolon and P. Boischot: The activity of the biological phenomena in peat. The relative passivity of peat from the biological point of view is due to the poverty of the medium in nutritive % elements, and especially phosphoric acid, and the results of the partial sterilisation of peat by heat cannot be attributed to destruction of toxins or to an action on the protozoa.—A. Quidor and Marcel A. Herubel: The psycho-physiology of visual phenomena.—Paul Benoit: The polar globules of the egg of Tubularia mesembryanihemunt.—Jean Camus, J. J. Gournay, and Fiterre: The mechanism of insipid diabetes.—E. Lesne, L. de Gennes, and Guillaumin: The action of light on the variations of calcemia in rickets.—A. Juillet: Remarks on the note by MM. Chevalier and Mercier on the pharmacodyamic action of the insecticidal principle of pyrethrum flowers.
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Societies and Academies. Nature 112, 304 (1923). https://doi.org/10.1038/112304a0
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DOI: https://doi.org/10.1038/112304a0