John Snow (the physician)

John Snow was a pioneering 19th-century British physician known for his work in public health and epidemiology. He is most famous for tracing the source of a cholera outbreak in London in 1854 to a specific water pump on Broad Street. By mapping cases and analyzing water sources, he demonstrated that contaminated water, not miasma (bad air), was responsible for the disease spread. His methods laid the groundwork for modern epidemiology and emphasized the importance of sanitation and clean water in preventing disease. Snow’s work significantly advanced understanding of how diseases spread and how to control them.