The revival of hynotism as a means for treating psychologic disorders has stimulated the public's interest in this controversial subject prematurely. However, the author, writing for the public, has succeeded in presenting the outlines of hypnotism understandingly and accurately. He describes the rise of animal magnetism under Mesmer's influence and its decline caused by bias within medical circles. Hypnotism later revived under medical auspices but again declined as a result of its use as a direct attack on symptoms rather than on their pathogenic complexes. The author proceeds from individual hypnotism to describe examples of mass suggestion and to reveal how crowds have been influenced. This social phenomenon is of topical interest and highlights the value of the book for the education of the public.