JOHANNES NICOLAUS BRONSTED (1879Though J. N. Bransted is most widely known for his l'undamental contributions to the modern picture of acids, hases, neutral salt effect and related topics, these studies by no means constitute the only reasons for his international reputation as a physical chemist. Born a t Varde, Denmark, on February 22, 1879, he recaved his higher education a t the University of Copenhagen and has served his alma mater as professor since 1908. Students have come to him from many lands, particularly America, and a constant stream of papen has issued from h ~ s study and laboratory. The main lines of his interests can he summarized: (1) studies of chemical ailjnity (thermodynamic theory of solutions, reactmns in the soltd state, allotropic and racemic transformations); (21 interaction theory of electrolytes (solubility of salts in salt s o u t ~ o n stheory of specific interaction, influence of medium); (3) separation of isotopes (with G. Hevesy); (4) protolytic theory of acids and hases, and of acid and basic catalysis (fundamental definitions of acids and hases, acid-base strengths in relation to charge and solvent, nitramide catalysis and other reac-
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tions subject to protolytic catalysis); (5) theory of reaction velocity in ionic systems, including experimental studies involving the theory of kinetic salt effect (primary and secondary);
