John Snow and the 1854 London Cholera Outbreak

In the early and mid 19^th century the sanitary conditions in poor London were poor to say the least. With Bazalgette’s sewers still five years away from even being started, the Thames was effectively a giant sewer, with the effluvia and waste of the city running directly into the river, and the cesspools in peoples’ basements perpetually overflowing into the streets. It is no surprise then, that London, and indeed most of the world, suffered the odd outbreak of cholera – a disease passed on by ingesting the bacterium vibrio cholerae through contaminated water or food.

There had been a cholera pandemic in London in 1832 which spread throughout the country and went on to kill an estimated 55,000 people in the UK. Another outbreak in 1848-49 killed 52,000 people in England and Wales, and the outbreak of 1854 killed over 10,000 people in London.

The city was in panic, and in Broad Street, Soho - which seemed to be the epicenter of the outbreak – 127 people died in three days. The popular theory at the time was that such diseases were caused by miasma – or ‘bad’ or smelly air. The general consensus being that if air smelled bad, it contained disease. Physician John Snow, however, was not a believer of this theory.

Snow published ‘On the Mode of Communication of Cholera’ in 1849. His theory being that cholera was caused by the contamination of drinking water and “always commences with disturbances of the functions of the alimentary canal.” (The ‘pipes’ in the body that takes food from mouth to anus)

This theory went largely ignored by the medical establishment and authorities and was opposed by a local water company near one London outbreak. Everybody continued to blame the, “miasma” or bad air that they believe was the culprit of all diseases. People began to flee London, fearing a repeat of the Great Plague of 1666. Three-quarters of Soho’s population had left within ten days of the start of the outbreak.

Snow lived in the district and interviewed the victims’ families. His research showed that virtually all of them lived near the water pump on Broad Street, but that Soho streets closer to another pump had fewer fatalities. He examined a water sample from the Broad Street pump under a microscope and found “white, flocculent particles.” He went to the Board of Guardians of St. James’ Parish and asked them to remove the handle and disable their pump. They weren’t convinced their water was polluted, but with little else to do and the city in turmoil, they agreed.

As Snow himself said in a letter to the editor of the Medical Times and Gazette:

“On proceeding to the spot, I found that nearly all the deaths had taken place within a short distance of the pump. There were only ten deaths in houses situated decidedly nearer to another street-pump. In five of these cases the families of the deceased persons informed me that they always sent to the pump in Broad Street, as they preferred the water to that of the pumps which were nearer. In three other cases, the deceased were children who went to school near the pump in Broad Street...

With regard to the deaths occurring in the locality belonging to the pump, there were 61 instances in which I was informed that the deceased persons used to drink the pump water from Broad Street, either constantly or occasionally...

The result of the inquiry, then, is, that there has been no particular outbreak or prevalence of cholera in this part of London except among the persons who were in the habit of drinking the water of the above-mentioned pump well.

I had an interview with the Board of Guardians of St James's parish, on the evening of the 7th Sept 7, and represented the above circumstances to them. In consequence of what I said, the handle of the pump was removed on the following day.”

The handle was removed and the water pump no longer used by local people as a source of drinking or washing water and cases dropped almost immediately.

Map Showing the Location of the Pump (centre) on Broad Street, Soho, 1854

However, the epidemic seems already to have been on the wane, and if Snow’s hypothesis was correct and the Broad Street pump had caused the cholera, why did people who lived elsewhere contract the disease, when some local people remained well?

After more research, it turned out that three of the non-local cases had taken a drink from the Broad Street pump. Also, a local workhouse had its own water well, and very few of the residents there got cholera during the outbreak. Workers at a local brewery got free beer as a perk. They hardly ever drank the water, and none of them got sick.

The source of the cholera outbreak in Soho was soon found: a cholera-infected baby whose nappy wash-water was emptied into a cesspool three feet away from the Broad Street well, and the cesspool had leaked directly into the water source. It was common at the time to have a cesspit under most homes. Most families tried to have their raw sewage collected and dumped in the Thames to prevent their cesspit from filling faster than the sewage could decompose into the soil. The Soho cholera contamination caused more than 600 deaths in the area.

The Handle-Less Pump

A plaque and a handle-less pump now stand as a monument to Snow near the site of the original pump in Soho.

The Plaque on the wall of the John Snow Pub

The exact pump location (on the renamed Broadwick Street) is marked by a colored paving slab outside the John Snow pub.

The John Snow pub was built in the 1870s and was originally called the "Newcastle-upon-Tyne."  Although John Snow was apprenticed in 1827 to a Newcastle-upon-Tyne surgeon, William Hardcastle, there is no evidence that the previous name of the inn was other than fortuitous.

In May 1955, on the occasion of the centenary of John Snow's researches into the causes of the cholera epidemic of 1854, its name was changed to the John Snow.