Welch, William Henry (1850–1934)

US pathologist and bacteriologist who discovered the micro-organism Clostridium welchii, which causes gas-gangrene. He advanced the sciences of pathology and bacteriology in the USA, especially at his own university in New York, with his high-calibre teaching and research.

Welch was born in Norfolk, Connecticut and studied medicine at Yale and at several German universities. He held the chair of pathology at Johns Hopkins University from its foundation 1884 until 1918. Upon his retirement, he went on to become the founding director of the Schools of Hygiene and Public Health and the History of Medicine at Johns Hopkins.