In Mécanisme de la physionomie humaine, the great nineteenth-century French neurologist Duchenne de Boulogne combined his intimate knowledge of facial anatomy with his skill in photography and expertise in using electricity to stimulate individual facial muscles to produce a fascinating interpretation of the ways in which the human face portrays emotions. This book was pivotal in the development of psychology and physiology as it marked the first time that photography had been used to illustrate, and therefore 'prove', a series of experiments. In this volume, Andrew Cuthbertson has provided an English translation of Duchenne, complete with a reproduction of the marvellous Album of photographs. The four commentary chapters by modern experts describe the relevance of Duchenne's findings to the fields of experimental psychology, plastic surgery, neurology and physiology. This book will therefore be valued by all those who deal with facial expression, including psychologists, physicians and those involved in the fine arts and photography.