Societies and Academies

Abstract

PARIS. Academy of Sciences, July 29.—M. Ed. Perrier in the chair.—G. Humbert: Ternary indefinite quadratic forms.—J. Boussinesq: The fundamental formula of Tresca for punching a cylindrical block of lead.—G. Bigourdan: Delisle at the Hôtel de Taranne; Lalande, Bailly, and Coulvier-Gravier at the Luxembourg.—M. Batland: The use of lime-water in the preparation of munition bread. An account of some experiments made in 1917 by order of the Minister for War on the use of lime-water in bread-making.—P. Bruère and Ed. Chauvenet: Zirconium nitride. Starting with the ammonia compound of zirconium chloride, ZrCl4.4NH3, a rise of temperature gives successively the amide, Zr(NH2)4, the imide (impure), Zr(NH)2, and finally, at about 350° C, the nitride, Zr3N4. This last appears to be the only nitride, and no evidence of the compounds Zr2N3 and Zr3N8 has been obtained.—M. Verzat: The measurement of temperature in very deep soundings. Two thermometers were cut at a temperature (40° C.) lower than that expected; after remaining at the bottom for an hour they were raised, and some mercury was found to have escaped. Comparison with a standard then showed the temperature (62.5° C.) at which the mercury exactly filled the tube, and thus gave indirectly the temperature at the bottom, 1616 metres from the surface. This gives a rise of 1° C. for every 32.3 metres depth.—F. Morvillez: The leaf-trace of the Caealpine Leguminosae.—H. Colin and Mile. A. Chaudim: The law of action of suerase. The deviation from Wilhelmy's formula is less marked as the ratio of saccharose to sucrase diminishes.—E Ladreyt: Epithelial regeneration. Besides normal physiological Renovation, epithelium may abnormally be regenerated at the expense of conjunctive tissue.—A. Besredka: Experimental paratyphoid fever B. The mechanism of immunity in paratyphoid B. Vaccination by the mouth.—H. Bordier: A radio-therapic unit of quantity. The unit is based on the amount of iodine set free from a 2 per cent, solution of iodoform in chloroform. It has been proved that the iodine liberated is regular, and proportional to the time of irradiation by the X-rays. The unit is then defined as the quantity of X-rays capable of setting free 0.1 milligram of iodine in 1 c.c. of a 2 per cent, solution of iodoform in chloroform, thickness 1. cm., and in the dark.—A. Paine and A. Peyron: Seminome of the testicle of the rabbit, with graft and generalisation to the second generation.