Societies and Academies

Abstract

LONDON. Chemical Society, April 22.—Prof. W.A. Tilden, F.R.S., president, in the chair.—The following papers were read:—The velocity and mechanism of the reaction between potassium ferricyanide and potassium iodide in neutral aqueous solution, by F. G. Donnan and R. le Rossignol. The velocity of this reaction can be investigated by titration of the iodine liberated; the simplest interpretation shows that it is quinquemolecular.—A microscopic method of comparing molecular weights, by G. Barger. Small quantities of the two solutions are introduced into a capillary tube, where they form bi-concave, discoid drops, care being taken to use the solutions alternately, so that each drop of one solution is enclosed between two drops of the other. The capillary tube is then sealed at both ends, and the length of each drop is measured microscopically from day to day until no change in volume is apparent. At this point the solutions are equimolecular.—Note on the spectrum of pilocarpine nitrate, by W. N. Hartley. The author states that the curve recently described by Dobbie as that of the ultra-violet absorption spectrum of pilocarpine nitrate is that of nitric acid slightly modified by the alkaloid present.—Isomeric change of dipropionanilide into propionyl—aminopropiophenone, by Dr. F. D. Chattaway. Under the influence of various catalytic reagents, e.g. zinc and hydrogen chlorides, dipropionanilide, like diacetanilide and dibenzanilide, undergoes transformation into propionyl-p;aminopropiophenone; the latter and some of its derivatives are described.—Note on the formation of di- and hexamethylammonio-cadmium chlorides, by W. R. Lang. Dry methylamine and cadmium chloride react at — 11° to form a white powder of the composition CdCl2,6CH3.NH2. This, when heated to 100°, furnishes a stable substance of the composition CdCl2,2CH3.NH2.