Dr. John Snow

Londoners had already experienced the cruelty of cholera epidemics numerous times. They knew about the severe vomiting and diarrhea, extreme dehydration, and death that would come within hours or days. Still, the outbreak of 1854 was far worse than much of what had taken place before. It was among the worst cholera outbreaks London had ever known. In one neighborhood, ten percent of the people died in the first week alone.

The “Blue Death,” as doctors referred to cholera because of the bluish-grey skin discoloration of the sick, had a name and history, but no one had proven how people became ill. Some believed the disease spread through poisonous air, a theory known as miasma. It seemed to make sense. The smell of decay lingered wherever cholera struck. Others, though, believed cholera was a disease of the blood because the veins of the afflicted turned blue. Some even argued that it was a form of divine punishment. And since doctors did not understand why the disease spread, there were no effective treatments to manage outbreaks. The best people could do was flee the area or light tar in the streets and carry satchels filled with lavender or herbs, hoping to purify the air, mask the stench, and possibly save lives.

Dr. John Snow disagreed with all these theories. Quiet and reserved by nature, he abstained from alcohol, practiced vegetarianism, preferred science books to company, and was widely considered eccentric. But he was also one of the finest physicians in London, perhaps in the world. By the time the 1854 outbreak began, John was in his early forties and already revered for his pioneering work in anesthesia.

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Sources:

• Avdulla CS, Tachirai N. John Snow: The Pioneer of Modern Epidemiology and Anesthesia. Cureus. 2024 Aug 23;16(8):e67602. doi: 10.7759/cureus.67602. PMID: 39310587; PMCID: PMC11416802.
• Ball, Laura. “Cholera and the Pump on Broad Street: The Life and Legacy of John Snow.” The History Teacher, vol. 43, no. 1, 2009, pp. 105–19. JSTOR, http://www.jstor.org/stable/40543358. Accessed 27 Jan. 2026.
• BROWN, P. E. “JOHN SNOW—THE AUTUMN LOITERER.” Bulletin of the History of Medicine, vol. 35, no. 6, 1961, pp. 519–28. JSTOR, http://www.jstor.org/stable/44446835. Accessed 27 Jan. 2026.
• De Hert, Stefan. “A Short History of Anaesthesia Before 1846.” European Society of Anaesthesiology and Intensive Care, https://esaic.org/a-short-history-of-anaesthesia-before-1846/
• “John Snow’s Map,” https://www.arcgis.com/apps/PublicInformation/index.html?appid=d7deb67f810d46dfacb80ff80ac224e9
• Snow, John, and Richardson, Benjamin Ward. Snow on Cholera: Being a Reprint of Two Papers. United Kingdom, Commonwealth Fund, 1936.
• Tulchinsky TH. John Snow, Cholera, the Broad Street Pump; Waterborne Diseases Then and Now. Case Studies in Public Health. 2018:77–99. doi: 10.1016/B978-0-12-804571-8.00017-2. Epub 2018 Mar 30. PMCID: PMC7150208.
• Wikimedia Commons, Wikimedia Foundation, https://commons.wikimedia.org/wiki/File:John_Snow.jpg & https://en.wikipedia.org/wiki/File:Snow-cholera-map-1.jpg & https://commons.wikimedia.org/wiki/File:Ether_inhaler,_c._1846,_developed_by_William_T._G._Morton_-_National_Museum_of_American_History_-_DSC06167.JPG