<P> Hypnosis was used by field doctors in the American Civil War and was one of the first extensive medical application of hypnosis . Although hypnosis seemed effective in the field, with the introduction of the hypodermic needle and the general chemical anesthetics of ether in 1846 and chloroform in 1847 to America, it was much easier for the war's medical community to use chemical anesthesia than hypnosis . </P> <P> The neurologist Jean - Martin Charcot (1825--1893) endorsed hypnotism for the treatment of hysteria . La méthode numérique ("The numerical method") led to a number of systematic experimental examinations of hypnosis in France, Germany, and Switzerland . The process of post-hypnotic suggestion was first described in this period . Extraordinary improvements in sensory acuity and memory were reported under hypnosis . </P> <P> From the 1880s the examination of hypnosis passed from surgical doctors to mental health professionals . Charcot had led the way and his study was continued by his pupil, Pierre Janet . Janet described the theory of dissociation, the splitting of mental aspects under hypnosis (or hysteria) so skills and memory could be made inaccessible or recovered . Janet provoked interest in the subconscious and laid the framework for reintegration therapy for dissociated personalities . </P> <P> Ambroise - Auguste Liébeault (1864--1904), the founder of the Nancy School, first wrote of the necessity for cooperation between the hypnotizer and the participant, for rapport . Along with Bernheim, he emphasized the importance of suggestibility . </P>

The physician who pioneered the study of the human subconscious was