Why It's Really John Snow Who Drinks and Knows Things

J Cucchiara and Dani Cucchiara

If the title grabbed your attention, you've most likely seen Game of Thrones. In season 6, episode 2 of Game of Thrones, we hear the character Tyrion Lannister (Peter Dinklage) state, “That’s what I do: I drink and I know things.” This is obviously not the character Jon Snow (Kit Harington) from the show, but there IS a real-life John Snow who deserves that kind of accolade.

In another time and place lived a hero named John Snow. This may sound like an introduction to a Game of Thrones, but it’s actually a chapter taken from our own past – in this case, London, England circa 1854. The story has been told numerous times by women and men of science and medicine.

A series of cholera outbreaks in 1832 and 1849 killed  14,137 people in London. In 1854, the third outbreak, part of a global pandemic reached the Soho district of the city of Westminster in London. This outbreak was responsible for the deaths of 616 people. As a local physician, Snow was concerned that his patients were dying and the ones who weren’t were fleeing the city.

At the time, germ theory, the idea that disease was caused by pathogenic microorganisms, didn’t exist. The best explanation for how people were getting this disease was “bad air,” or the established medical term “miasma.”  The only way to change the air was to change where you lived, so people were trying to outrun the disease by moving somewhere else.

Snow didn’t subscribe to the miasma theory. Instead, he thought that cholera was being transmitted via water, but he couldn’t prove it, and the solution needed to be based in fact. Snow knew that he needed numbers, so he drew a map and began to collect data by going door-to-door. Snow interviewed people at each business and residence about those who had contracted and died from cholera.

The darkened lines on the map show the number of people who died at each location. Using this data, Snow was able to show how the number of people dying were distributed throughout Soho. In addition to this information, Snow also plotted the locations of water pumps located throughout the neighborhood. Careful examination of this map shows the Broad Street pump at nearly the exact center of the cholera outbreak. The further away from the pump, the less people dead from cholera.

Despite his diligence, Snow still needed more proof cholera was being spread from the Broad Street water pump. According to the working theory of miasma, bad air may have been centered around that area due to the deaths or the amount of open sewage. The proof Snow needed was also on the same map. Two locations within the Soho neighborhood, a workhouse and brewery, were close to the broad street pump but had significantly lower deaths than the surrounding homes and businesses. Both of these locations had their own water supply. It was enough proof for Snow to convince the local authorities to remove the pump handle from the Broad Street pump. This led to a significant reduction in people dying of cholera.

Later on, Snow found that infected body fluids were being dumped into cesspool located near the well and water pump. The pathogen that causes cholera, Vibrio cholerae, was able to gain access to the well water, infecting people who drank from the water pump. The disease had mostly run its course by the time they removed the pump handle, but what Snow accomplished was the prevention of subsequent outbreaks. By performing a simple statistical analysis of his cholera maps, he became the founding father of epidemiology.

Image of the John Snow Pub in Soho, London.

It may be the story that makes John Snow famous today, but the Soho cholera mystery is not the only contribution he made to modern medicine. In fact, John Snow also pioneered the use of ether as an anesthetic. Prior to this there was no reliable anesthetic for people undergoing difficult procedures or surgery. He was able to calculate safe dosages and develop procedures for administering ether in a safe way. Ether allowed physicians to operate on people in an unconscious state so they would remain still and experience no pain until after the procedure was over.

Unlike his Westerosi counterpart, John Snow was a teetotaler. In one address given before he became an MD, he warned people of the evils of alcohol, saying, “I feel it my duty to endeavour to convince you of the physical evils sustained to your health by using intoxicating liquors even in the greatest moderation; and I leave to my colleagues the task of painting drunkenness in all its hideousness, of describing the manifold miseries and crimes it produces, and of proving to you that total abstinence is the only remedy for those evils.”

Apparently, he DIDN’T drink after all. He just knew things. Ironic that a brewery played a part in the events that put him in the history books. Ironic also that in Soho today there is a pub named after him. I wonder how he would have felt about that.

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