PARIS. Academy of Sciences, July 18.—G. Bigourdan: The differential determination of time with high precision.—A. Desgrez. and J. Meunier: The Pressence of lithium and in the teeth and in human bones. The chemical. The existence of lithium and strontium as normal constituents of bones and teeth is definitely established. Lithium is present as phosphate and strontium as carbonate.—Léon Guillet; The properties of pure aluminium. Aluminium containing 99.8 per cent, of the metal is now commercially obtainable. Details of its electrical and mechanical constants are given. These do not differ greatly from those of the ordinary aluminium containing 05.l per cent, of impurities.—Louis Ravaz was elected correspondant for the section of rural economy in succession to the late A. Balland.— Georges Bourguignon: Chronaxy of the muscles of the leg of the rabbit. Comparison with the chronaxy of the leg muscles of man in the normal state and in lesions of the pyramidal bundle.—Eugène Slutsky: A limiting theorem relating to series of eventual quantities.—Edm. Lahaye: A new method of integration of certain groups of differential equations.—S. Stoïlow: Continued transformations and Picard's theorem on integral functions.—René Lagrange: Certain suites of polynomials.—Krawtchouk: The poles of meromorph functions.—D. Riabouchinsky: Fluid movements round infinitely near solids.—Henri Mémery: The sun. and the atmosphere. In attempts to find a relation between variations of solar phenomena (suiispots) and temperature variations in western Europe, results are more likely to be obtained by making comparisons each day than by using annual averages.—J. Struik and Norbert Wiener: The relativist theory of quanta.—H. L. Vanderlinden: The fine spectrum structure in the gravinc field of the sun.—R. Anthouard: Tho conditions of discontinuity of discharge in gases. Considering the tube through which the discharge passes as a condenser, a formula is developed which has been experimentally confirmed.—Max Morand: The distribution of tho electric field in the dark space.—E. Delauney: The atomic character of some properties of the X-rays. Experiments with irradiated mixtures of barium chloride and strontium chloride show that the numbers obtained for the intensity of the fluorescence do not follow the additive law; the intensity of fluorescence increases much less rapidly than the proportion of barium chloride.—Ny Tsi Ze: Changes in the optical properties of quartz under the influence of the electric field.—Paul Soleillet; Tho influence of the magnetic field on the polarisation of the resonance radiation of cadmium.—Ch. Bouhet: The elliptical polarisation produced by reflection at the surface of liquids.—A. Andant and E. Rousseau: Tho resonance power of some metallic salts irradiated by filtered light from a mercury arc. The phenomenon of resonance in the presence of a manganese salt described in a previous communication, is not an isolated experimental fact. The same phenomena are found in the presence of salts of magnesium, sodium, potassium, and uranium.—P. Bonèt-Maury: The vaporisation of polonium. Experimental results obtained by the method described in an earlier communication.—M. Wilmet: A method for the rapid estimation of hydrogen phosphide in a gas mixture. The gas is allowed to react with a solution of mercuric chloride and the hydrochloric acid produced determined volumetrically.—V. Auger and C. Eichner: A compound intermediate between v vanadium sulphate V2O5 n SO3 and vanadyl sulphate (VO) SO4.—W. N. Ipatieff and B. N. Dolgof: The hydrogenation of tetraphenylmethane and p-oxytetra-phenylmethane under pressure. With hydrogen under 80–100 atmospheres pressure and at 275°–285° C., tetraphenylmethane gives eyclohexane and tricyclo-hexylmethane: p-oxytetraphenylmethane under similar conditions gives cyclohexanol, dicyclohexyl-methane and some tricyolohexylmethane.—Jacques de Lapparent: The texture of bauxites and their origin.—G. Dubar: The metamorphic strata of o Betchat (Ariège).—F. Dienert: The influence of the soil on the cooling of waters.—E. Blanchard and J. Chaussin: The antagonism between chlorides used in large quantities and sulphates on the course of the development of wheat and oats.—J. Pien: The influence of calcium cyanamide on the reaction of the soil. Calcium cyanamide causes an increased alkalinity of soil for five to ten days: later, there is a slight reduction, but the final result is a clear variation of the pH of the soil towards alkalinity.—Th. Bieler-Chatelan: Chestnuts, ferns, and brooms. In spite of their preference for soils containing little or no chalk, the chestnut, fern, and Spanish broom may flourish in places where calcium carbonate renders the soil distinctly alkaline.—P. Petit and Richard: The saccharification of the dextrins.—Charles Pérez: A protelian parasitism of Nectonema.—F. d'Herelle and E. Peyre: Contribution to the study of experimental tumours.—Daniel Chevrier and Max Salles: The sterilisation of potable waters by electrolysis. The apparatus proposed consists of a metal tube forming the cathode with a fine platinum wire, placed along the axis of the tube, as anode. The voltage used is 110 to 120 volts.—Roger Douris and Charles Mondain: The differentiation of pathological sera by means of their dehydration figures.