Prentiss, in Science, October 3, 1890, has collected numerous instances of sudden canities, several of which will be given:-- "In the Canada Journal of Medical Science, 1882, p. 113, is reported a case of sudden canities due to business-worry. The microscope showed a great many air-vesicles both in the medullary substance and between the medullary and cortical substance. "In the Boston Medical and Surgical Journal, 1851, is reported a case of a man thirty years old, whose hair 'was scared' white in a day by a grizzly bear. He was sick in a mining camp, was left alone, and fell asleep. On waking he found a grizzly bear standing over him. "A second case is that of a man of twenty-three years who was gambling in California. He placed his entire savings of $1100 on the turn of a card. He was under tremendous nervous excitement while the cards were being dealt. The next day his hair was perfectly white. "In the same article is the statement that the jet-black hair of the Pacific Islanders does not turn gray gradually, but when it does turn it is sudden, usually the result of fright or sudden emotions." D'Alben, quoted by Fournier, describes a young man of twenty-four, an officer in the regiment of Touraine in 1781, who spent the night in carnal dissipation with a mulatto, after which he had violent spasms, rendering flexion of the body impossible. His beard and hair on the right side of the body was found as white as snow, the left side being unchanged. He appeared before the Faculte de Montpelier, and though cured of his nervous symptoms his hair was still white, and no suggestion of relief was offered him. Louis of Bavaria, who died in 1294, on learning of the innocence of his wife, whom he had put to death on a suspicion of her infidelity, had a change of color in his hair, which became white almost immediately. Vauvilliers, the celebrated Hellenist, became white-haired almost immediately after a terrible dream, and Brizard, the comedian, experienced the same change after a narrow escape from drowning in the Rhone. The beard and the hair of the Duke of Brunswick whitened in twenty-four hours after hearing that his father had been mortally wounded at the battle of Auerstadt.