Virology in order to immunize others. In 1717 Lady Mary Wortley Montagu observed the practice in Istanbul and attempted to popularize it in Britain, but encountered considerable resistance. In 1796 Edward Jenner developed a much safer method, using cowpox to successfully immunize a young boy against smallpox, and this practice was widely adopted. Vaccinations against other viral diseases followed, including the successful rabies vaccination by Louis Pasteur in 1886. The nature of viruses however was not clear to these researchers. In 1892, the Russian biologist Dmitry Ivanovsky used a Chamberland filter to try to isolate the bacteria that caused tobacco mosaic
History of smallpox identified as smallpox. Early in history, it was observed that those who had contracted smallpox once were never struck by the disease again. Thought to have been discovered by accident, it became known that those who contracted smallpox through a break in the skin in which smallpox matter was inserted received a less severe reaction than those who contracted it naturally. This realization led to the practice of purposely infecting people with matter from smallpox scabs in order to protect them later from a more severe reaction. This practice, known today as variolation, was first practiced in China in the