The same authority also says: "It has been known for a long time that if the attention is directed toward any bodily organ, abnormal sensations may be caused in it, and disease may be developed. The renowned Dr. John Hunter said: 'I am confident that I can fix my attention to any part, until I have a sensation in that part.'" Dr. Tuke says that these "are words which ought to be inscribed in letters of gold over the entrance of a hospital for the Cure of Disease by Psychopathy." Hunter's confident assertion is the more interesting because, drawn from his own experience, it shows that the principle is not confined in its operation to the susceptible and nervous, but operates even on men of the highest mental endowment. We have examples from the literature of the seventeenth century, showing how the expectation of a complaint will produce it. In 1607 an ignorant English physician told a clergyman's wife that she had sciatica, although there was, in reality, nothing the matter with her sciatic nerve. Her attention was thereby directed to it and a severe attack of sciatica was the result. When a person inexperienced in medicine reads carefully the symptoms of some disease, he is apt to begin an attentive search for those symptoms and to end by fancying he has them. Seasick persons have been relieved of their nausea by being made to bail a leaking boat from the fear that it would sink. All their attention was thereby diverted from themselves. Many can recall how children, and grown persons, too, have forgotten all about their alleged intense thirst, as soon as their attention was diverted. Some persons, after eating something which they fancy is a trifle indigestible, center their attention upon the stomach, expecting symptoms of indigestion, and are often not disappointed. A man who had good reason to fear hydrophobia, determined that he would not have it. The pain in the bitten arm became intense, and he saw that he must have something to divert his attention from the wound and his danger. He therefore went hunting, but found no game. To make amends, he summoned a more inflexible will and exerted at every step 'a strong mental effort against the disease.' He kept on hunting until he felt better, and he mastered himself so perfectly that he probably thereby warded off an attack of hydrophobia. Accordingly as we center our attention upon one thing or another, we largely determine our mental happiness and hence our bodily health. One person, in walking through a noble forest, may search only for spiders, and venomous creatures, while another confines his attention to the singing birds in the branches above. One reason why travel is such a cure for diseases of body and mind is because so many new things thereby come in to claim the attention and divert it from its former objects. The following expression from Dr. Tuke should be remembered: '_Thought strongly directed to any part tends to increase its vascularity, and consequently its sensibility_.'"