Svengali, the malevolent hypnotist in a sensationally successful novel published by George du Maurier in 1894, became such a well-known character in the culture of the period that his name entered the dictionary as one who exerts a malign persuasiveness on another. This book explores the origins and impact of Svengali and his helplessly mesmerized female victim Trilby in an age already rife with discussions of race, influence, and the unconscious...