You Know Everything, John Snow: Cholera in the 19th Century

The story usually goes like this:

In 1856 there was a dreadful Cholera outbreak on Broad Street in Soho. John Snow looked at a map of deaths and concluded that all victims had been drinking from the same water pump. So he shut the pump off and deaths stopped. Then the government supplied freshwater for all and cholera stopped. Now a pub is named after the notorious teetotaller and vegan next to the spot of said pump. John Snow gets a two page spread in GCSE History textbooks and we all wonder why Victorians couldn’t have got to the root of these nasty pandemics earlier.

A portrait of John Snow (1813-1858), British physician. SOURCE: Public Domain

This version is right but in the same way that the Treaty of Versailles caused World War Two is right. It’s correct but a bit more detail would help. Cholera, or ‘The Indian Cholera’, as many liked to call it, was a dreadful disease. It could kill a healthy person in four hours, usually by severe dehydration. Patients experienced a sudden increase in diarrhoea then vomiting and cramps. They would excrete a cloudy liquid rather like rice water. Very quickly the eyes sunk into the head, fingers and toes shrunk to a third of their size, the patient could speak only in a whisper and blood became like a deep dark jelly. When cut, patients did not bleed.

Cholera first arrived in Britain, Sunderland to be precise, in 1831. Yet it had been sporadically recorded in India for two centuries. Fourteen years previous it killed 9,000 people over five days in Bundelkand. A British soldier wrote, ‘The invasion was so sudden that horsemen were stricken from their steeds and the roads were covered with the dying.’ The increasingly connected world of the nineteenth century gave Cholera to opportunity to spread. It’s progress west across the Middle East and north into Russia baffled all who observed it. An Indian doctor recorded:

‘The disease would sometimes take a whole circle around a village and leave it untouched. Yet after weeks or months it would suddenly return. Sometimes after a run on one side of the river Ganges it would instantly switch to the other side and kill there instead.’

Its arrival in the densely packed cities of the west was as grim as expected. It killed almost 10% of New Orleans. Where there was overcrowding; cholera was rampant. In Moscow rumours spread that the disease was a hoax spread by greedy doctors. Hospitals were attacked and Tsar Nicholas himself told off a crowd for behaving, “like they were Polish or French.” In the winter of 1831 as Hamburg descended into chaos, a British ship fled the port destined for the north of England.

Now at this stage we should consider why Cholera was do devastatingly effective. It spread through the excrement of the victim. The colour of this ‘rice water’ meant that it would blend quite easily into drinking water. There was practically no colouration. All that was required for it to infect was the slightest of leaks from a drain or cesspit into a water supply. As you can imagine, Victorian cities provided countless grim opportunities for effortless transmission.

Furthermore, almost all doctors believed that disease spread by dirty air particles called miasma. Now one can see the logic. Disease spread in terribly unhygienic areas and terribly unhygienic areas have terrible smells. This belief lingered through to the twentieth century with even Florence Nightingale passionately holding onto the miasma theory until her death in 1910!

Step up John Snow. John Snow was not liked and barely respected by the medical community. He was criticised for creating theories then seeking out the supporting evidence. When he found what he was looking for, he was generally derided as a broken clock… The fact that he didn’t touch alcohol or meat didn’t help his reputation either. Yet Snow applied data where others did not. He also applied his deep knowledge where others did not. His premise was simple:

Diseases which start in the blood lead to fever, headaches and temperatures. Diseases starting with the digestion system begin with diarrhoea and vomiting. Cholera started with the later. What were all victims sharing? Water.

The difficulty with proving his theory was that most outbreaks took place in slums where seeking evidence was tricky. An 1849 outbreak in the genteel Albion Terrace in Battersea gave him the grim opportunity he needed.

On 26th July 1849 a violent storm struck Britain’s metropolis. Three days later the first case of cholera was reported on the street. By the middle of August 10 of the 17 houses had fatalities. The case seemed straightforward to traditional medics. Albion Terrace was 300m from an open sewer, one house had eight cart loads of maggot ridden rubbish in the basement and the storm flooded three houses with bad smells subsequently emanating from their sinks. Snow thought otherwise. Why were houses closer to the open sewer not effected? Why were only some on Albion Terrace affected? The investigation found that the houses all shared a water supply connected to a tank in their gardens. 24cm above each house’s water tank was a pipe from their cesspits. Some of these pipes were damaged, most likely in the storm, and so leaked into the water supply. So the ‘rice water’ evacuations of the first patient rapidly infected others through the underground water and waste systems. Snow had his proof but the red herrings of the nasty smells were enough to leave the medical establishment unconvinced.

Let’s jump to 1854 and the now famous Soho Cholera outbreak. Within a week at the end of the summer 668 lost their lives in this poverty-ridden community. There were an average of 18 people in each house whose access to water was a pump which worked for less than an hour a day. And the water came from the Thames. The river was so polluted that the last salmon caught was in the 1830s. One wouldn’t make a reappearance until 1986! Snow interviewed as many residents as he could and plotted the location of all deaths on a map. He concluded that the common denominator seemed to be proximity to the water pump on Broad Street. A tap nearby was surrounded by only ten deaths and a lot of the families here got their water from the Broad Street pump. They didn’t trust their local one…

Image showing the compact streets of 19th century London

He successfully petitioned the local council to turn off the tap and the pace of deaths eased off. But, rather frustratingly, as the graph below shows they were reducing anyway. The powers that be remained unconvinced.

Chart showing the death rate and the effects the closing of the Broad Street pump had on cases

Snow died of a stroke four years later. His research at this time was not trusted by the London water companies or his fellow medical professionals. The tide began to turn when a local Reverend Henry Whitehead successfully received permission to have the Broad Street well excavated. He found that a nearby cesspit wall had rotten and was leaking into the water supply. His conclusion was that the soiled nappy of a five month old cholera victim named Frances Lewis was the direct cause of the deadly outbreak. 

In time all of London would be provided with fresh water (And the Thames embankment) through the mighty construction projects of Joseph Bazalgette. Clusters of cholera were stamped out by this mammoth project. Possible without John Snow? Maybe. Possible without parliament leaving the city during the Great Stink? Maybe not. But that’s another story…

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