Societies and Academies

Abstract

LONDON. Society of Public Analysts, Dec. 2.—H. W. Buston: A micro-method for the determination of uronic anhydride groups in pectic substances. The method involves distillation with dilute hydrochloric acid and measurement of the resulting carbon dioxide. The process is complete in 60-70 min., and the results are as accurate as those given by the macro process.— N. E. Cocchinaras: The composition of linseed oil. Prom the results of bromination experiments it is concluded that the linolenic acid of linseed oil is present in only one isomeric form, namely, that yielding the crystalline hexabromide. Less than two per cent of oleic acid was found, and the solid fatty acids were proved by fractional distillation to consist only of palmitic and stearic acid.—T. Hedley Barry: Oil from Malayan Aleurites Montana and the properties of Hong Kong oil. Oil from the seeds of Aleurites Montana from the Malay States had an abnormal refractive index, which was lower than any recorded for the oil of A. Fordii. It also gave abnormal results in the polymerisation test.—S. G. Clarke and W. N. Bradshaw: The calcium fluoride method for the determination of fluoride, with special reference to the analysis of nickel-plating solutions. In the presence of an excess of calcium chloride to reduce the solubility of the precipitate, calcium can be quantitatively precipitated as calcium fluoride without simultaneous precipitation of calcium carbonate. Iron does not interfere if it is first reduced to the ferrous condition by means of hydrazine, and the adsorption of calcium sulphate is largely prevented by the presence of ammonium chloride, which increases the solubility of the calcium sulphate.