Snow, Dr John

John Snow (1813–1858) was an English physician and a pioneer of modern epidemiology. His landmark dot map of the 1854 cholera outbreak in Soho, London, is widely credited with transforming the understanding of disease transmission. By meticulously plotting the locations of cholera victims, Snow revealed a clear concentration of cases around the Broad Street water pump. Acting on this evidence, he famously persuaded officials to remove the pump handle—an intervention that swiftly curtailed the outbreak. Snow’s map provided compelling visual proof that cholera was waterborne, not airborne, and his work led to lasting reforms in London’s water and sanitation systems. It also laid the foundation for the modern field of public health. Early editions of Snow’s map are scarce, including those published by the River Pollution Commission in Hansard in 1874. We stock original and mid-20th-century reprints of both his classic untitled Broad Street map and the expanded version showing local sewer improvements and the suspected locations of plague pits. You can read more in our blog post on Snow’s revolutionary dot maps of the 1854 Soho cholera outbreak.