Societies and Academies

Abstract

PARIS. Academy of Sciences, August 9.—M. Henri Deslandres in the chair.—A. Blondel: A new optical or electrical apparatus for the measurement of oscillations of velocity and angular deviations. The method is based on the registration on a photographic film moving at a uniform rate of the angular displacements of a disc carrying a series of equidistant slits, the disc being attached to the axis of the machine under examination. An application of the method to the study of an internal-combustion engine is given.—M. Petot: Extract from a letter to M. Appell concerning the spherical representation of surfaces.—B. Deiaunay: The number of representations of a number by a binary cubic form with negative discriminant.—F. Carlson: The zeroes of the series of Dirichlet.—C. Fremont: Cause of the frequency ol breakages of rails at their extremities.—J. Rey; Perrot's experiment relating to the movement of rotation of the earth. In 1859 Perrot observed certain rotations in a jet of water flowing from a hole in the base of a cylindrical vessel, and regarded these as due to the rotation of the earth. Laroque, in 1860, concluded that the observed phenomena were not connected with the earth's rotation, but many phenomena in geophysics have since then been explained on the assumption of the validity of Perrot's views Experiments are described which lead to the conclusion that Perrot's views are erroneous, and fully confirm Laroque's criticisms.—H. Godard: Observations of the periodic comet Tempel II. made at the Bordeaux Observatory with the 38-cm. equatorial. The apparent positions of the comet and comparison stars for July 24, 25, and 27 are given.—A. Buhl; The symmetries of the electromagnetic and gravific field.—E. Darmois: The influence of ammonium molybdate on the rotary power of malic acid. A crystallised compound of malic acid and ammonium molybdate has been isolated. Its rotatory power is very high (+ 219°), and constant over a wide range of concentrations. There is a probability that this is not the only complex compound formed when ammonium molybdate is added to solutions of malic acid.—A. Portevin: The similitudes of micrographic aspect existing in various states between the iron-carbon (steels), copper-tin (tin bronzes), copper-zinc (brasses), and copper-aluminium alloys (aluminium-bronzes).—J. Bougault and P. Robin: Catalytic oxidation by unsaturated bodies (oils, hydrocarbons, etc.). Dichloroethyl sulphide, which alone or in solutiori is unaffected by oxygen, in presence of turpentine readily oxidises on exposure to air, the sulphoxide SO(CH2.CH2Cl)2 being formed. By a similar oxidation, thiodiglycol in presence of citral is readily oxidised by air to the sulphoxide SO(CH2.CH2.OH)2. —R. Souèges: The embryogeny of the Compositæ. The last stages of the development of the embryo in Senecio vulgaris.—P. Lesage: Experiments utilis-able in plant physiology on osmosis and on the aspiration due to evaporation.—M. and Mme. G. Villedteu: The action of rain on the deposits of copper mixtures on plants.—J. Amar: How to determine the output of workmen.—A. Migot: The formation of the axial skeleton in Eunicella (Gorgonia) Camolinii.—MM. Fauré-Fremiet, J. Dragoiu, and Mile. Du Vivier de Streel: The histochemical differentiation of the fœtal pulmonarv epithelium in the sheep.—M. Piettre and A. Vila.: Some properties of serine.—C. Lebailly: The virulence of the milk in apthous fever. The milk is virulent before any appearance of symptoms characteristic of the disease, the high temperature being the only indication of departure from the normal healthy condition.—E. Alilaire and E. Fernbach: Some observations on the culture of the tubercle bacillus in non-glycerinated media.