One of the most notable events in the history of medicine was the introduction of the systematic practice of _preventive inoculation against small-pox_. It is so generally taught that this is entirely due to the efforts of Jenner--or, rather, we are so often allowed to think it, without being taught otherwise--that the measure deserves an historical sketch. The communication of the natural disease to the healthy, in order to afford protection,--or, in other words, the communication of small-pox to prevent the same,--reaches back into antiquity. It is mentioned in the Sanscrit Yedas as performed by Brahmins, who employed pus procured from small-pox vesicles a year before. They rubbed the place selected for operation until the skin was red, then scratched with a sharp instrument, and laid upon it cotton soaked in the variolous pus, moistened with water from the sacred Ganges. Along with this measure they insisted upon careful hygienic regulations, to which, in large measure, their good results were due. Among the Chinese was practiced what was known as "pock-sowing," and ten centuries before Christ the Celestials introduced into the nasal cavities of young children pledgets of cotton saturated with variolous pus. The Arabians inoculated with needles, and so did the Circassians, while in North Africa incisions were made between the fingers, and among some of the negroes inoculation was performed in or upon the nose. In Constantinople, under the Greeks, the custom had long been naturalized, and was practiced by old women, instructed in the art, who regarded it as a revelation of Saint Mary. The first accounts of this practice were given to the Royal Society by Timoni, a physician of Constantinople, in 1714. The actual introduction of the practice into the West, however, was due to Lady Mary Wortley Montagu, who died in 1762, and who was wife of the English Ambassador to the Porte in 1717. She had{226} her son inoculated in Constantinople, by Maitland, and on her return to London, in 1721, her daughter also was inoculated. During the same years experiments were undertaken by Maitland upon criminals, and, as these turned out favorably, the Prince of Wales and his sisters were inoculated by Mead. The practice was then more or less speedily adopted on this side of the Atlantic, but suffered occasional severe blows, because of unfortunate cases here and there, such as never can be avoided. The clergy, especially, using the Scripture, as designing men can always do, became warm opponents of the practice, and stigmatized it as an atrocious invasion of the divine prerogative. Nevertheless, in 1746 the Bishop of Worcester recommended it from the pulpit, established houses for inoculation, and thus made it again popular. In Germany it was generally favored, and a little later came into vogue in France and Italy. In 1757 Robert Sutton, near London, professed to have made fifteen thousand inoculations without a single fatal case; he kept