This book contains, in popular and concentrated form, a survey of present day knowledge of vitamins, hormones and other minute essentials for health. After an introductory chapter on the deficiency diseases, the writer goes on with a discussion of "the vitamin alphabet," including interesting historical data and discussing the more important phases of present knowledge of vitamins. The two chapters on this subject, consisting of 91 pages, contain chiefly well established facts, presented in a style which should meet the approval both of the general reader and of the biologist. The latter might perhaps find statements with which he does not agree—for instance: "That mild scurvy is widespread in this country, not only in children but also among adults, is evidenced by unsound teeth, dental caries and diseased gums." On the whole, however, such controversial matter is treated separately in succeeding chapters which contain a discussion of vitamins and dental