Is the introduction of disease germs into the system, usually by puncture of the skin or hypodermic injection; many diseases so introduced assume a mild form, and render the subject not liable to the severe form. Inoculation for smallpox, the virus being taken from actual smallpox pustules, was practised by the ancient Brahmans and by the Chinese 600 years before Christ, and its practice continued in the East. It was introduced to this country from Turkey in 1717, and extensively practised until superseded by Jenner's discovery of vaccination at the end of the century, and finally prohibited by law in 1840. Inoculation has been found successful in the prevention of other diseases, notably anthrax, hydrophobia, and recently malaria.