PARIS. Academy of Sciences, August 21.—M. Atnrai dGautier in the chair.—The president announced the death of Albert Ladenburg, correspondant in the section of chemistry, and gave a short account of his work.—H. Deslandres and L. d'Azambuja: The velocities of rotation of the black filaments (flocculi) in the upper layer of the solar atmosphere. A historical sketch of the work done on the dark flocculi since their discovery by Hale and Ellermann in 1903, with special reference to the work done at the Meudon Observatory since 1908. Five diagrams are given showing successive positions of a filament on different dates, and four tables analysing various negatives.—J. Boussinesq: The spontaneous vibrations of a free bar, cooling by contact at its extremities and by radiation or convection at its lateral surface.—Kr. Birkeland: The sun and its spots. A description of experiments made with a magnetic globe as a kathode in a large discharging vessel, and a discussion of the possible bearing of these experiments on the theory of the sun. Seven photographs of the luminous phenomena observed are reproduced, and the author concludes that in the evolution of the solar system, electrical and magnetic forces must be regarded as playing a part comparable with gravitation.—A. de la Baume Pluvinel and F. Baldet: The spectrum of the Kiess comet (1911b). The Kiess comet was sufficiently bright during the second fortnight in July to allow of the photography of its spectrum by the prism-objective method. The wave-lengths and aspect of the bands measured are given in a table. The comet gave no continuous spectrum. Portions of the Swan spectrum and cyanogen spectrum are identified, and comparisons are made with the Johannesburg (1910a) and Morehouse (1908c) comets.— Michel Fekete: Some generalisations of a theorem of Wcierstrass.—Georges de Bothezat: A method for the experimental study of the deadening of the oscillations of certain systems in motion in a fluid.—Em. Bourquclot: The glucoside from the leaves of the pear tree, its presence in the leaves of several varieties, its presence in the trunk and root. The existence of a true arbutine in the leaves, branches, and roots of the pear has been proved.—E. L. Trouessart and E. G. Dehaut: The, wild and domesticated pigs of Sardinia and Corsica;—-Édouard Chatton: Some parasites of marine copepods observed by M. Apstein. —E. Roubaud: New biological researches on the solitary wasps of Africa; evolution, variations, disturbances of the maternal instinct under the influence of hunger.—C. Schlegel: The development of Maïa squinado.—Maurice Arthus: The intoxications produced by snake venom.— J. Basset: The determining cause of “typhoid fever of the horse” (influenza, grippe, pasteurellosis, pferdestaupe, pink eye).—Maurice Piettre: A mode of resorption of fatty reserves.