THE sixth part of this important supplement deals with the proteinases, in particular with tryptase, pepsinase, chymase (rennet) and also papainase: it follows the plan already indicated. Frequent use of the supplement confirms the opinions already expressed as to its utility and the clarity with which the great amount of information is presented. Sections dealing with the occurrence and distribution of these enzymes may be particularly cited for their completeness and value to the physiological chemist. Naturally, exact directions are given for the preparation of the crystalline enzymes, and one could have wished for some photographs of these crystals in order to bring home to the sceptics their beauty and the magnitude of the achievement.
Die Fermente und ihre Wirkungen
Von Prof. Dr. Carl Oppenheimer. Supplement. Lief. 6 (Band 2, Specieller Teil: Haupt-Teil 13–15). Pp. 783–942. (Den Haag: Dr. W. Junk, 1936.) 10 florins.