Societies and Academies

Abstract

PARIS. Academy of Sciences, September 30.—M. Des Cloizeaux, President, in the chair.—Presentation of the fourth sheet of the Bulletin of the International Committee for preparation of a map of the heavens; meeting of Committee at Paris Observatory, by M. E. Mouchez. Five other Observatories (Vienna, Catania, Mexico, Manilla, and the Vatican) have been added to the original sixteen. Each Observatory will have to take about 700 photographs in the zone alloted to it, and it is hoped to finish the work in three or four years. A central office for utilizing the results will be necessary.—Addition to the theory of thin weirs extending throughout the breadth of the bed of a water-course; calculation of variations in the contraction of the outflowing sheet at its lower face, by M. J. Boussinesq.— On the last communication of Halphen to the Academy, by M. F. Brioschi.—On the denomination of the industrial unit of work, by M. H. Resal. He advocates the unit of 100 kilo-grammetres, to be called the quintalmetre.—On the application of high temperatures in observing the spectrum of hydrogen, by MM. L. Thomas and Ch. Trépied. The electric arc is found a sure and comparatively easy way of making hydrogen sufficiently luminous for spectroscopic observation, even with large dispersions; (four jets of the gas were made to converge conically towards an axis coinciding with that of the carbons).— On concatenation (enchainement) of the atomic weights of the elements, by M. Delauney. He shows that the atomic weights may be joined together by addition in each case of the square root of a whole number, which is variable, but always harmonic (not containing any other prime factors than 1, 2, 3, and 5).—Combinations of cupric oxide with amylaceous matters, sugars, and mannites; new reagents for proximate analysis, by M. Ch.-Er. Guignet. Solutions of cellulose, also dry starch, or inuline, give well-defined combinations with oxide of copper, when put in contact with its solution in ammonia. Some sugars (pure glucose from honey, galactose, &c.) quickly precipitate copper ammonio-sulphate (but not the oxide); and while inverted sugar does not precipitate the sulphate, a previous addition of glucose produces a deposit of the glucosic combination (which does not retain ammonia). Mannite and dulcite, &c., yield at once blue precipitates in an ammoniacal sulphate of copper solution, which reagent is useful with decoctions of vegetable matters, as most substances in these are not precipitated by it.—On the number and calibre of nerve-fibres in the common oculomotor nerve, in the new-born and in the adult cat, by M. H. Schiller. The number does not increase during life (or increases very little); average 2942 in the kitten, 3035 in the cat. The calibre is increased six or eight times.—On the preceding investigation, by M. Aug. Forel. Various researches point to the stability of the nervous elements during life, and this he regards as very important for explanation of the phenomena of memory.—On the vitality of trichinæ, by M. Paul Gibier. He submitted small pieces of fresh pork with numerous trichinæ (which were much more lively when brought out of their cysts into a water-heated vessel than those of the salt meat) to a temperature of 20° to 25° below zero, for about two hours, and found the animals, on reheating, as lively as before.—The innervation of the osphradium of mollusks, by M. Paul Pelseneer. Like the other sensorial organs of mollusks, the osphradium proves to be innervated by the cerebral ganglion.—On the Spongeliomorpha Saportai, a new Parisian species, by M. S. Menier.