Societies and Academies

Abstract

PARIS Academy of Sciences, August 23.—M. Wurtz in the chair. -The following papers were read:—Meridian observations of small planets at the Greenwich and Paris observatories during the second quarter of 1880, communicated by M. Mouchez.— Distinctive character of the pulsation of the heart, according as the right or left ventricle is examined, by M. Marey. During a stoppage in respiration the right heart shows a diminution in amplitude of pulsations, owing to pulmonary resistance, while the left heart shows a slight increase. If through any influence lowering the arterial tension (such as muscular exercise, inhalation of nitrite of amyl, &c), waves be produced in the aorta, these waves cause in the tracing of pressure of the left ventricle a bifurcation or trifurcation of the summit (according as two or three have occurred during systole). The right ventricle does not show these waves, unless in vestige, and by propagation from the neighbouring part.—Remarkable example of vertically-ascending lightning, by M. Trecul. This was during a storm on Aug. 19. The sparks appeared to come from some lightning conductors in the place. Some rose singly and disappeared at a small height, expanding into a magnificent, nearly circular flash, the light of which diminished from centre to circumference. In one case two luminous columns rose simultaneously and parallel, and at a certain height precipitated themselves against each other at a right angle.—The death of M. Godron, correspondent in botany, was announced.—The sun would act inductively on the earth even if its magnetic power were simply equal to that of our globe. Induction of the moon by the earth and diurnal lunar variation of terrestrial needles, by M. Quet. The induction of the earth by the sun could be insensible only if the magnetic power of the latter were much below that of the former, which is not probable. The induction of the moon due to its revolution round the earth produces an electromotive force twenty-one times less than that the effects of which are rendered sensible by an experiment made on the earth, and consequently is itself sensible. As the induction of the satellite by rotation of the earth is about twenty-seven times greater than the foregoing, the resultant will be a sensible force with sensible reaction on particular earth-currents, leading to a daily variation of needles according to lunar hours.— On the variations of the coefficient of dilatation of glass, by M. Crafts.—On tungstoboric acid, by M. Klein.—On the products of distillation of colophony, by M. Renard.—On the project of establishment of a station for hospitable purposes at the sources of the Ogooue, by the French Committee of the African Association, by M. Mizon.