A SECTION of Messrs. Hermann's "Actualites Scientifiques et Industrielles" series of publications is being devoted to investigations of the effects of radiation on living organisms ; it is under the charge of Prof. N. Marinesco, director of research in the Institute of Physico-chemical Biology, Paris. Two parts dealing with ultra-sound waves and their properties have already appeared: (1) "Proprietes piezo-chimiques, physiques et biophysiques des Ultra -sons. Technique des ondes elastique de haute frequence", and (2) "Proprietes des Ultra-sons. Destruction des micro-organismes. Preparation des colloides a basses temperatures. Reactions explosives. Reactions photochimiques". Both are written by Prof. Marinesco. The first 56 pages and 5 plates (15 francs) describes the electro-elastic properties of quartz, the production of stationary waves in liquids, the intensity of the radiation, the pressure it exerts and the absorption it undergoes. The second, of 68 pages and 7 plates (18 francs), describes the effects of ultra-sound waves in sterilizing water and milk, in producing emulsions, in detonating explosives and in accelerating chemical reactions with special reference to those in photography. Many of the plates are reproductions of photographs taken by the author. Bibliographies are provided.