We observe in this list that fear not only affects the mind and the nervous and muscular tissues, but the molecular chemical transformations of the organic network, even to the skin, the hair, and the teeth. This might be expected of a passion which disturbs the whole mind, which is represented or externalized in the whole body. Dr. Tuke reiterates the fact which has been so frequently observed, that epidemics owe a great deal of their rapid extension and violence to the panic of fear which exists among the people. When yellow fever, cholera, smallpox, diphtheria, and other malignant diseases obtain a footing in a community, hundreds and thousands of people fall victims to their own mental conditions, which invite the attack and insure its fatality. When the disease was new and strange, as the yellow fever was to the interior in its visitation in 1878, when the doctors were not familiar with it, the nurses not trained to it, the people, having no confidence in its management, lost hope, their fears became excessive, and consequent mortality was frightful. How does fear operate upon the body to produce sickness? By paralyzing the nerve centres, especially those of the vasomotor nerves, thus producing not only muscular relaxation, but capillary congestions of all kinds. This condition of the system invites attack, and there is no resilience, or power of resistance. The gates of the citadel have been opened from within, and the enemy may enter at any point. What determines the specific nature of the disease which attacks a person thus prostrated by fear? Men are frequently prostrated by fear in storms or fire or earthquakes or accidents, and no disease results. It is because they have been not thinking and brooding over any special morbid conditions. But in an epidemic, say of yellow fever, the subjects connected with the disease are strongly pictured on the mind. They are talked of, read about, discussed and written about, until the mind is full of images of fever, delirium, black vomit, jaundice, death, funerals, etc. When such is the case, no microbes or bacteria are needed to produce an outburst of yellow fever. The whole mass of horrors already stamped upon the mind is simply reflected and repeated in the body. "As a man thinketh, so is he," said Solomon. Thoughts become things, apprehensions take form and substance, and lo! the disease. In the height of his happiness and prosperity, Job permitted himself to brood in silent fear over the possibility of losses and misfortunes, and he had at last to exclaim, "The thing which I greatly feared has come upon me." Sudden and great fears are not frequent. The fears of every day, the constant apprehensions and anxieties of life, which are really fears of impending evil, prey upon our vitality and lessen our power of resisting, so that any passing disease may be photographed on our minds and seen upon our bodies.