"Thomas W., about twenty years of age, the son of a milkman, was tall, fleshy, good looking, slightly bronzed, hair intensely black, stiff, wiry, and rather inclined to curl. His general appearance was that of a healthy and well-formed man, used to light work, but much exposure in the open air. In the year 18—one of his thoughtless companions told him (what was not true) that a girl in the town was going before the magistrate on the morrow to swear him father of her child. Poor W. was dumfounded. The announcement had given his whole frame a severe shock; the gall of bitterness had entered his heart, and the mind was under the baneful influence of its power. He hastened home, and sought relief in his bedroom. Sleep was denied him, for his brain was on fire. He saw nothing but disgrace coming from every angle of the room. Such was the mental agitation produced by a silly trick. Early morning brought no relief; he looked careworn, distressed, and his hair was changed from its natural tint to that of a light 'iron-gray color.' This, to him, was a great mystery. In the course of the following day the stupid trick was explained, but the ill effects of it lasted for a long period. Nearly twenty years after, although his health was fair, the mental powers retained signs of the severe shock they had received; his hair was perfectly gray, and a medical friend of mine who met him received the impression that he would carry the marks of this folly to his grave. "I know of a captain of a vessel, under forty years of age, who suffered shipwreck twice. On the first occasion (in which he lost all hope) his hair quickly turned gray; and on the second, some considerable time afterward, his hair be-