Ionization of Proteins and Antagonistic Salt Action

In 1899 Wolfgang Paul2 and the write? independently reached the conclusion that electrolytes when acting on proteins formed ion-protein compounds. The writer anticipated that these ionproteins would explain the mystery of many life phenomena. He was especially interested in one of the most universal physiological actions of salts; namely, the antagonistic salt action, for which the annihilation of the effects of a high concentration of a salt with univalent cation, e.g. NaCl, by a low concentration of a salt with bivalent cation, e.g. CaC12, is perhaps the best known example. Although he and many others tried to demonstrate this type of antagonism in proteins they never succeeded. It was a further disappointing fact that Hardy3 found that globulins apparently form electrically neutral compounds with neutral salts and this seemed to harmonize with the older observations of Liebermann and Bugarszky. Pauli had expressed the idea that a low concentration of salts ionizes globulins and thereby causes their solution, but even he assumed not a real chemical combination but adsorption between the globulin and the salt. Meanwhile, many workers, and especially Pauli and his pupils, had developed a number of methods for discriminating between the chemical behavior of ionized and non-ionized proteins, but