In 1854, physician John Snow identified the source of a cholera outbreak in Soho, London, tracing it to a contaminated water pump. His groundbreaking work established a critical link between water quality and disease transmission, challenging prevailing medical theories of the time. Snow's findings not only contributed to the understanding of cholera but also laid the foundation for modern epidemiology and public health practices.

John Snow’s empirical detective work in 1854 reinforced the Victorian faith in observation and logic, paralleling the realist novel’s focus on social detail and causality. This contributed to the literary theme of the city as a complex, decipherable organism, inspiring poets to examine urban life through a critical lens.