PARIS. Academy of Sciences, Jan. 24.—E. Goursat: A problem of the theory of surfaces.-F. E. Fournier: The inclination 0, always favourable to the speed of a ship, that its satellite wave gives to its plane of flotation, in a calm sea.—F. W. Perkins: The resolution of the problem of Dirichlet.—Andr5 Roussel: The ensembles of equally continuous functionals.G. Sugot: The gyroscopic movement of a projectile. -P. Dejean: The influence of compression on the fragility of steel. The existence of a limit of fragility. -Leon Bouthillon: The inclination of [electromagnetic] waves and directed systems.—E. Brylinski: The relative velocity of the earth and the neighbouring ether. A. Picard and E. Stahel have described the results of experiments which they regard as opposed to the conclusions of Miller, based on experiments at Cleveland and at Mount Wilson. The author shows that the two series of experiments, regard being had to the possible errors, are really in agreement.-Leon and Eugene Bloch: The spark spectra of bromine. A list of lines in the E1 and E2 spectra between wavelengths X6353 and x2338.-Paul Riou: An apparatus for measuring the rates of absorption of gases by liquids. A description, with diagram, of an apparatus for determining the rate of absorption of a gas by a liquid.-Mario A. da Silva: A new determination of the period of polonium. The method is based on the determination of the ionisation produced in pure argon by the a-rays of polonium: the period found is 140 2 days.—J. Huggett and G. Chaudron: The temperatures of magnetic transformations in the system iron-ferric oxide.—Jolibois and Chassevent: An apparatus for the thermal analysis of plaster. Details of a calorimetric method which gives the velocity of hydration of plaster of Paris, capable of controlling and classifying commercial products more conveniently than by chemical analysis.—P. Job: The cuprammonium ion and its stability. Determinations of the equilibrium constant under varying conditions show that the Cu(NH3), ion is the only ion stable at the ordinary temperature.—Marcel Delepine: The oxidation with permanganate of pyridine and the pyridine nucleus. The pyridine nucleus is readily oxidised by acid permanganate solutions, the nitrogen appearing mainly as ammonia with some as nitric acid.-Marcel Godchot and Pierre Bedos: The action of organo-magnesium compounds on the oxide of cycloheptene. Cycloheptene oxide is isomerised by the action of CH3MgI, and the cycloheptanone thus formed (suberone) then reacts with the magnesium compound in the ordinary manner.-V. Hasenfratz: The preparation and properties of l-arabonic and I-ribonic lactones.-L. Royer: The regular joining up of cubic salts on mica.-N. Menchikoff: The crystalline and volcanic rocks of the centre of the Libyan desert.L6on W. Collet and R. Perret: The geology of the Col d'Anterne and of the Cirque des Fonts (Sixt Alps, Haute-Savoie).-Albert Baldit: Magnetic measurements in the south-west of the Central Massif.-K. Tsukamoto: The transparency of sea water for the extreme ultra-violet. From experiments on synthetic salt solutions, it is concluded that absorption in the extreme ultra-violet by sea water is due to the presence of small quantities of bromides.-Pierre Allorge: The vegetation of the sphagnum peats of Galiad (Spain).-L. Blaringhem: The affinities of the wild wheats Triticum cegilopoides and T. monococcum, demonstrated by their reciprocal hybrids.Emile Andre: A new and abundant source of trilaurin; the seed of the Mahuba, Acrodiclidium Mahuba. Of No. 2992, VOL. 119] the family of the Lauraceve, this seed contains about half its weight of a fat consisting of fairly pure trilaurin.-H. Lagatu and L. Maume: Control of the mode of nutrition of a perennial plant (vine) in a given soil receiving a given manure.-Henri V. Vallois: The variations of the spinal muscles in the higher primates.-P. Vignon: The primitive nervation of the wings of insects and the changes from the original plan in the Orthoptera.-Jules Amor: Observations on biological similitude.-Georges Bourguignon: Double innervations in the human organism, discovered by pathological and normal electrophysiology and controlled by anatomy.-Henri Pisron: The law which connects the surface of the wings with the weight of the individual in the same animal species, and some problems concerning the flight of insects. The wing surface in one species studied (Libellula sanguinea) is a linear function of the weight supported. -G. Lefrou: The anticoagulating power of certain dyes and organic arsenic compounds.-RaymondHamet: The point of vascular attack of the ergot alkaloids.-Andr6 Bonot and Th6ophile Cahn: The estimation of arginine in pure proteids and tissues by a modified Jansen method.-E. Roubaud and J. Colas-Belcour: The action of diastases in determining the eclosion of the egg in the mosquito of yellow fever (Stegomyia fasciata).-Bordier: General principles and technique of the new treatment of HeineMedin's disease (infantile paralysis).