The author of this volume was for over eighteen years resident physician of the Tombs in New York and for nearly three years medical assistant of the district attorney. His discussion of crime is therefore based on study of several hundred thousand people accused of criminal acts. His book is enlivened by many anecdotes of the great and near great criminals with whom he has had contact. The chapters of the book discuss the prison physician, narcotic addiction, the relationship of mental and moral defects and of insanity to crime, the uses of probation, the detention prison, court procedure and the penal institution. This is a first hand account of the work of the prison physician, which may be read with interest by every one interested in crime and its detection and also by those interested in prison reform.