John Snow and the Broad Street Pump

2013-08-24 16.14.10In the summer of 1854, the central London neighbourhood of Soho was struck by a sudden cholera epidemic. Local physician John Snow identified the Broad Street pump as the source of the outbreak, preventing further spread of the disease. These days, the affected neighbourhood is home to many pubs and cake shops, prompting my friends to organise a “cholera and cake” pub crawl with out-of-town visitors this past weekend.

The Broad Street pump is not longer there, but in 1992 a symbolic pump was placed across the street from the John Snow pub, which is thought to have been the original location of the pump.

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Locating the source of the cholera epidemic was an especially impressive feat because the prevailing medical opinion at the time was that cholera was caused by “bad air”, and not by something you can find and eliminate. Germ theory hadn’t yet caught on, but John Snow was skeptical of the “bad air” theory, and suspected that there was something else.  He talked to lots of people in the affected area and in neighbouring streets, and he started to notice a pattern. Continue reading “John Snow and the Broad Street Pump”