Man's attempts to learn about aspects of the human body and its functions by observation and study of animals are to be found throughout history, especially at times and in cultures where the human body was considered sacrosanct, even after death. This book describes the origins and later development, especially in the eighteenth and nineteenth centuries, of comparative medicine and its interrelationship with medicine and veterinary medicine and the efforts of its practitioners to understand and control outbreaks of infectious, epidemic diseases in humans and in domestic animals. In the nineteenth century their efforts and increasing professionalism led to the creation of specialised institutes devoted to the study of comparative medicine. Paradoxically the first such institute, the Brown Institution, opened in London in 1871, despite the fact that the study of this branch of medicine in Britain had always lagged behind that in France and Germany. The book discusses the rise and fall of this centre and describes how it was soon overtaken in importance by the great institutes in Paris and Berlin and then, from the turn of the century, by American institutes, funded by private fortunes. This book sheds much new light on the medical and veterinary history of this period and will provide a new perspective on the history of bacteriology.