Knowledge concerning the drug problem presented by marihuana has come to most physicians through the somewhat sensational news stories in the supplements of the Sunday newspapers. Dr. Walton's exhaustive monograph concerning the narcotic principles of the drug is extremely timely. The book is factual but interestingly written. It covers the historical, botanic, pharmacologic, sociologic, legal and public health aspects of the use, or more specifically the misuse, of marihuana. There is a valuable chapter on nomenclature, which gives a complete glossary. The bibliography contains 419 references. The book should prove an invaluable reference for sociologists, public health officers and physicians.