As a particularly nasty novirus epidemic sweeps through London this winter, it's both fascinating and instructive to look back at a horrible cholera epidemic that hammered Londoners in 1854. The physician John Snow came to the city's rescue and saved countless lives when he did some innovative medical detective work.
Snow halted the outbreak by removing a single pump handle. Thanks to his analysis and prompt action, Snow is now regarded as one of the founders of epidemiology.
