An interesting phase of psychotherapy is found in the history of the applications of new scientific discoveries to medicine. The development of every physical science has been followed by an attempt to apply its new principles and discoveries to the treatment of disease. Such applications have nearly always been followed by excellent results at the beginning. But almost without exception, the medical significance of these discoveries has, after a time, been found to be nil. When these discoveries were made they became the center of public attention. The announcement of their application to medicine then seemed natural and produced a feeling that another great therapeutic principle had been discovered. Sometimes wonderful therapeutic effects were noted. The chronic diseases particularly were helped for some time, at least, and practically all the affections that have mainly subjective symptoms were greatly relieved, or actually cured. After a time, however, when the novelty of the discovery wore off, its suggestive power was lessened and then the remedy lost its therapeutic power.