The volume reviews the information at present available about enzymes used clinically, including trypsin, chymotrypsin, streptokinase, ribonuclease, deoxyribonuclease, hyaluronidase, and cholinesterase. The text covers the chemistry of enzyme action, the parenteral use of enzymes (not topical application), and the diagnostic use of enzymes, such as amylase, phosphatases, and others. Trypsin receives major emphasis in the text. It is regrettable that critical analysis of some of the clinical results with enzymes is not included. The volume, however, is interesting. It offers the reader considerable information regarding enzymes used in clinical medicine not at present available in any other single volume with which the reviewer is acquainted.