This volume explores topics usually skimmed over or only tangentially treated in the current crop of books on contemporary biology for the laymen. Locke, a former research associate at Rockefeller University, defines enzymes, the versatile protein catalysts of nature. He takes them apart chemically, shows how they're put together, how they work, what they do and how they're manufactured in the cell. He covers such fashionable subjects as the origin of life, the genetic code (with the accent here on the ""one gene-one enzyme"" doctrine of Beadle and Tatum), the role of enzyme inducers and repressors, activators and inhibitors. In addition he very refreshingly discusses such old-fashioned topics as digestion, respiration, nutrition and the importance of vitamins and minerals. He describes in detail the use of enzymes in making beer, wine, bread; in wound-healing and in insecticides, up-dating this material in the light of recent research, and enumerating some of the latest enzyme-containing products, such as the newer bleaches. He writes in a scholarly way, occasionally repetitious, but very thorough. The book is good solid reading enlightened by fascinating tidbits the author all too often throws away. Such pure gold includes explanations of why permanent waves work, why cyanide is an effective poison, why you can't put fresh pineapple in Jello, why peroxide works as an antiseptic for cuts, how insects develop resistance to DDT, what causes albinism, why penicillin kills bacteria and how enzymes can break up blood clots.