William Jenner, British physician, 1873.
© Science Museum / Science & Society Picture Library
Chromolithographed caricature by Spy, subtitled 'Physic'. Sir William Jenner (1815-1898) established the difference between typhus and typhoid fevers in 1851. Typhoid fever is contracted from food or water contaminated by Salmonella typhi; typhus is spread by lice. Doctors had previously diagnosed both conditions as 'continued fever'. Jenner's discovery had important implications for the treatment of both diseases. He was a profesor at University College, London, from 1848 to 1879, became physician-in-ordinary to Queen Victoria in 1862, and to the Prince of Wales the following year. From the magazine 'Vanity Fair'.