INOCULATION

the communication Of disease accidentally or intentionally to a healthy subject by the introduction of certain products of disease into the body through the skin or the mucous membrane. _The chief diseases so transmitted in man are anthrax, hydrophobia, small-pox, and syphilis. Before Jenner introduced vaccination (q.v.), I. of smallpox was practised. The disease as thus transmitted was far le dangerous than the ordinary small-pox, and, further, rendered the inoculated subject much le liable to a future attack. Its disadvantages are obvious, in that it tended to keep the disease alive, and further to increase its spread, but it was invaluable to those who had been inoculated, and was of great service prior to Jenner’s discovery. In 1840 the practice of I.fwith smallpox was forbidden by law. Pasteur’s treatment for hydrophobia and all serum injections are based on a similar principle to that explained above.