Arthur Roupert had retired some two years before from regular medical practice, in which, as all the world knows, he was undoubtedly the first authority on disease and aberrations of the brain and nervous system, devoting his attention more particularly to those riddles of obscure and baffling disorders to which he so often supplied strange and correct answers. He was possessed of an ample competence, and so, finding that his large professional practice did not permit him the leisure which was necessary for these exploratory studies, he had, though always willing to be consulted by his colleagues, thrown up an active career for one of research. He wanted to learn rather than to practise, and without precisely mistrusting the methods which had earned him so brilliant a success, had inferred the presence of huge fields of the unknown, huge expanses of further possibilities which would perhaps put utterly out of date the most advanced of theories and treatments hitherto recognized in his profession. At the time of his retirement he had once talked to me about the uncharted seas on to which he proposed to push forth. “The most advanced of actual practitioners,” he said, “are but groping in the dark on the threshold of real knowledge, feeling for the handle, fumbling for the bell. At the most, that is to say, in cases of brain disease and nerve disorder we try to get at the mind of the patient, and influence that, so that it, not we, may exert its healing power, and cure the imperfect functioning of the material part. Of course that is a tremendous step forward when we look at what medical science was twenty years ago, when doctors prescribed tonics, tonics to heal the physical damage caused by a disordered mind. But mind itself is but a very subordinate denizen in that house of mystery which we call man.