This volume has been revised, and certain sections have been rewritten. The text contains materials essential to students for a short course in chemistry entering medicine, bacteriology, nutrition and allied sciences. A discussion of optical isomerism has been brought up to date, glyceric aldehyde rather than lactic acid being used as an example, carbohydrate metabolism has been further developed and the section on chemotherapy, which contains newer drugs and antibodies, has been expanded. The vitamins have been brought up to date, and a chapter on blood has been added. The volume will be a good addition to a collection of books on physiologic chemistry.