Leonor Michaelis. Praktikum der physikalischen Chemie insbesondere der Kolloidchemie für Mediziner und Biologen. Berlin, 1921.

Thanks to the tremendous success of the applications of physical chemistry to medicine and biology (immunity, biological chemistry, the ionic theory of excitation), it is becoming more and more necessary for the physician and the biologist to become acquainted not only with the foundations of the theory of physical chemistry, but also with its methodology.

Michaelis’s little book, 160 pages long, sets forth the principal methods of physicochemical investigation, especially those necessary for the physician and the biologist. The book begins with two sections devoted to the quantitative determination of labferment and pepsin in gastric juice.

The second chapter deals with the precipitation of colloids from solutions. Chapter III presents certain experiments demonstrating the Tyndall phenomenon and ways of distinguishing it from fluorescence; it then sets forth methods for determining H and OH ions in solution (Chapter IV) and the question of the precipitation of colloids at a changing ion concentration.

Individual chapters (VI) are devoted to capillary constants, diffusion—osmosis and filtration (VII), swelling, viscosity, and the formation of jellies (VIII and IX).

Experiments on electrophoresis and electroendosmosis (X), on adsorption (XI), and on the action of enzymes (XII) are discussed in detail. The booklet concludes with an exposition of the methods for determining electrical conductivity, measuring electromotive forces, and reaction kinetics.

The booklet fills a very appreciable gap in the literature on applied physical chemistry.

P. Lazarev.