Societies and Academies

Abstract

PARIS. Academy of Sciences, June 16.-M. Leon Guignard in the chair.-MM. A. Lacroix and Tilho: A geological sketch of Tibesti, Borkou, Erdi, and Ennedi. The sedimentary formations.-G. Bigourdan: Work of the Naval Observatory. Historical account of observations made between 1752 and 1796.-H. Deslandres: Remarks on the constitution of the atom and the properties of band specfra.-C. Guichard: Isothermal surfaces.-E. Aries: The saturated vapour pressures and latent heats of evaporation of propyl acetate at various temperatures. From the equation of state developed in earlier communications, formulae are deduced and applied to the calculation of the vapour pressures and latent heats of evaporation of propyl acetate; the figures are compared with the experimental results of S. Young with very satisfactory agreement.-M. E. Mathias was elected a corre-spondant in the section of general physics in succession to M. Georges Gouy, elected non-resident member.-E. Kogbetliants: Trigonometrical series.- G. Reboul: The phenomena of luminescence accompanying the oxidation of potassium and sodium. This effect appears to be due to the formation and rupture of a skin of hydroxide; the presence of moisture is essential.-H. Abraham and Ei Bloch: The maintenance of mechanical oscillations by means of lamps with three electrodes.-G. Baume and M. Robert: A glass manometer with elastic walls. The instrument described and figured consists of a thermometer with a bulb made with thin flat walls. This is surrounded with a glass envelope containing the fas the pressure of which is to be measured. The apparatus can be' utilised as a null instrument by connecting one side to an ordinary mercury manometer, or can be used directly after calibration. A set of measurements of the pressures of nitrogen peroxide at different temperatures is given as an example of the application of the manometer.-A. Joannis: Some properties of the acid phosphates. An account of the action of liquid anhydrous ammonia on the mono- and di-alkali phosphates.-J. Guyot and L. J. Simon: The action of dimethyl sulphate on the sulphates of the alkalis and alkaline earths. A mixture of methyl sulphate and potassium sulphate in equi-molecular proportions when heated to 2000 C. reacts quantitatively to form potassium pyrosulphate and methyl ether. The action of sodium or lithium sulphate is similar, but the reaction is not complete.-Ch. Audebeau Bey: The lowering of the north of the Egyptian delta since the Roman Empire.-S. Stefanescu: The structure of the plates of the molars of Elephas indicus, and the different origin of the two species of living elephants. A study of the molars leads to the conclusion that the origin of Elephas indicus is quite different from that of Elephas africanus.-A. Baldit: Certain cases of diminution of the wind velocity with altitude.-M. Mascre: New remarks- on the rdle of the nourishing layer of pollen.-S. Posternak: Two crystallised salts of the phospho-organic reserve principle of green plants. The two salts, details of preparation and purification of which are given, have the compositions CeH12O27P6Ca2Na"and CaH15O2,P6Na12.-J. Amar: The haamatopneic coefficient.-P. Woog: The variable persistence of luminous impressions on different regions of the retina.-A. Robin: The soluble and insoluble nitrogen in the tissue of cancerous liver; new conception of the genesis of cancer.-H. Bierry: Proteid sugar.-H. Coutiere: The limb of the Arthropods.-E. Sollaud: The embrvonic development of the"Palasmonidse.-P. C. de Baillon: The existence in locusts and crickets of an organ serving for the rupture of the chorion at the moment of eclosion.-M. Baudouin: Mode- of ossification of the great trochanter in man of the polished Stone period.