How One Man Stopped Cholera
From the time he began his career as a medical apprentice, John Snow faced one of the deadliest foes in the world, as cholera overtook the population, killing thousands. His battle against the disease landed him in the history books—and his story is worthy of an epic biopic.
1. He Grew Up Poor
John Snow came from humble beginnings. Born March 15, 1813 in York, John was the oldest of nine children. His father was a laborer in a nearby coal terminal; as the family eked out an existence in one of York’s most downtrodden areas. But poverty wasn’t the only problem that the family faced.
2. He Wasn’t Sniffing The Smell Of Success
Living in such a poor neighborhood, John and his family were well-acquainted with the terrible sanitary conditions of their surroundings near the River Ouse. Exposure to contaminated runoff from nearby cemeteries and market stalls and even the presence of sewage were normal parts of the lad’s everyday existence. But John’s mother helped him find other things to dwell on.
3. He Didn’t Find Ignorance Blissful
John’s mother Frances used the money she’d acquired through an inheritance to enroll John in school. John quickly impressed his teachers with his math skills; it was apparent he was no ordinary youngster. It wasn’t long before a rare opportunity presented itself.
4. He Had A Ticket To Success
A doctor in nearby Newcastle got wind of young Snow’s reputation for mathematical brilliance. Recognizing Snow’s potential, the doctor offered to take the young man on as a medical apprentice. As the son of a laborer opportunities were few and far between—the 14-year-old Snow leaped at the offer.
5. He Was A Teenage Doctor
John Snow dove straight into his medical apprenticeship and learned quickly on the job. As he learned the ropes he treated patients for many different ailments, but one particular disease soon emerged that he would do battle with for the rest of his career.
6. He Had His First Close Encounter With Cholera
In 1832, he treated numerous patients stricken by a cholera outbreak at a nearby coal mine. This early exposure to the dreaded disease made a lasting impression on Snow. Seeing firsthand the ravages of cholera on the human body caused him to think more deeply about the disease’s cause.
7. He Learned The Standard Theory
John Snow knew from his studies that the dominant theory of cholera was that it was caused by breathing in foul air, called miasmas. As the theory went, bad soil containing decaying organic matter caused invisible clouds of the evil miasma that carried the fatal disease.
As neat and tidy as this all sounded, Snow was drawn to a very different theory.
8. He Had Other Ideas
There was one thing that set Snow apart from his peers and set him on the path to saving lives. A less accepted theory of cholera held that the disease was caused by polluted water and unsanitary conditions. Unlike most other doctors, Snow had grown up in unsanitary surroundings and he was immediately drawn to the water-borne theory of cholera.
But it was what he saw in the coal mine that really affected him.
9. He Saw The Terrible Conditions
As a young doctor who was still learning, John Snow noted several things about the cholera epidemic that didn’t fit with the theory he’d been taught. The victims of this outbreak were working deep down in mineshafts in appalling sanitary conditions with no separate toilet or handwashing facilities. The miners had no separate room in which to eat their lunches. That wasn’t the only thing that troubled him.
10. He Noticed The Symptoms
Snow reasoned that if cholera was caused by bad air, the lungs and airway of the victim should show some symptoms. Instead, he made a disturbing discovery. The disease always struck the digestive tract, with victims invariably suffering severe stomach cramping before becoming violently ill. The associated extreme dehydration was often fatal.
The mine outbreak eventually subsided, but Snow’s questions about what he’d seen continued to haunt him.
11. He Was A Medical Pioneer
After obtaining his medical degree, Snow became an anesthetist. He was soon using ether and later chloroform to drug patients for surgery. A pioneer in a field that was still in its infancy, Snow had to take great care in administering the chemical vapors. He also had to pay close attention to patient conditions and symptoms.
This experience helped Snow develop keen powers of observation, and a rigorous scientific approach to everything he did.
12. He Made A Name For Himself
By the early 1850s, John Snow had become known as the best anesthesiologist in London, assisting with hundreds of operations per year. His meticulous experimentation and observations of different concentrations of chloroform marked a major advance in pain management.
In 1853, Snow started to realize that his reputation in the new science went far beyond Soho.
13. He Had A VIP Patient
In 1853, Queen Victoria was about to give birth to her fifth child. Anxious to avail herself of an anesthetist to aid in the delivery, she sought out the best in the business. Doctors and other experts referred her to Dr Snow.
The delivery went so well that she would request Snow for the birth of her next child in 1857 as well.
14. He Debated His Colleagues
John Snow had developed a penchant for engaging his medical colleagues in spirited debates on whatever medical topic took his interest. He wasn’t shy about advancing his view that cholera was a water-borne illness, in stark opposition to older physicians who still held to the miasma theory. This highly contentious issue was on its way to taking center stage in the London medical community.
15. His Views Were Based On Experience
Snow’s own experience had convinced him that impure water was the cause of the recurring cholera outbreaks in England. He had worked hard to advance the field of anesthesiology and refused to let theories rule out what he could observe with his own eyes. Only one of the competing views on cholera could be correct—the truth would soon be impossible to ignore.
16. He Had Come Full Circle
In 1854, Dr Snow was busy with his medical practice in Soho, London. Soho was similar to the area of York where he had grown up, with animal enclosures and slaughtering plants producing a lot of waste. Compounding the problem, Soho wasn’t on the London sewer system. It was customary to dump waste into cesspits or the nearby Thames—a practice that was about to prove disastrous.
17. He Was Aware Of A Problem
By late August that year, John Snow was living in fear. He thought there could be a cholera problem brewing in the community. There were several cholera outbreaks around London that year and doctors in Soho worried that the scattered occurrences would eventually hit their area. In the prevailing unsanitary conditions, it was only a matter of time before the crisis hit.
18. He Was At The Center Of The Storm
The cholera outbreak Snow feared arrived in September. In the first three days of that month, 127 people in the Broad Street area of Soho fell to the deadly disease. Nurses, including the famous Florence Nightingale, worked round the clock to save lives at the nearby hospital. But if Snow thought the situation was desperate now, it was about to get a whole lot worse.
19. He Was Horrified
With over 20 years of medical practice treating every kind of ailment under the sun, John Snow was long accustomed to witnessing tragedy and suffering. But even he was alarmed at the spiraling situation. By September 10, over 500 lives had been lost in the densely populated area.
Though he struggled to process what he was witnessing around him, he began applying his analytical skills to halting the raging pandemic.
20. He Flew Into Action
With ground zero of the outbreak only a stone’s throw from Snow’s practice, he had been tracking the details of the case intently. It was obvious to him that it was the worst cholera outbreak in several years.
On September 3, determined to get to the bottom of what had caused the contagion, he headed to Broad Street.
21. He Found Himself In A Ghost Town
Walking through Soho, it was obvious to Snow that those residents who were able to leave had already cleared out of the area. By September 10, three-quarters of the neighborhood’s residents would flee the area. Anxious for first-hand information, and with few people lingering on the streets, he began knocking on doors.
22. He Canvassed The Neighborhood
During the outbreak, John Snow put his life on the line. He stuck around and went door-to-door through the Broad Street neighborhood, asking everyone who was still available to recount what they knew of what had happened. But interviewing all these people was no small task.
With the cholera outbreak still exacting its grim toll, there was little idle time for research. Snow needed help in his investigations, and eventually found a very capable partner in the area.
23. He Got A Helping Hand
Snow made contact with a local clergyman, Reverend Henry Whitehead. Whitehead had been wrenched by the upheaval in his neighborhood, and took a keen interest in Snow’s ideas about halting the spread of cholera. A compassionate man with strong ties to most of the people on Broad Street, he began to assist Snow in interviewing the residents.
As the two investigators learned more, Snow saw who were the hardest hit.
24. He Saw Who Was Hardest Hit
Snow and Whitehead soon realized that those who shared a common water supply were the worst affected by the disease. Nurses at the hospital had noticed that the “fallen women” of the area made up most of their patients. The general profile was of a neighborhood whose poorest residents were the hardest hit. That included the area’s very first victim.
25. He Heard A Heart-Rending Account
Snow interviewed Sarah Lewis, whose baby, Frances, had been the outbreak’s first victim. Lewis, who later lost her husband in the epidemic, moved Snow with her grief. But he noted an interesting fact from her account. Sarah said she always dumped her used laundry water into a cesspit that was not far from a pump on Broad Street that locals used for their drinking water.
26. He Heard An Interesting Tale
Snow’s inquiries soon brought him in touch with the Eley brothers, who owned a factory in the area. Many of their workers had either expired or fallen deathly ill. The Eleys’ mother and cousin had already been taken by cholera. But they lived several miles away in Hampstead. How had they come in contact with the disease?
27. He Found A Tell-Tale Clue
After interviewing the Eley brothers, Snow made a shocking discovery. It turned out that the brothers filled two huge tubs with water from the Broad Street pump each day for their workers. Knowing their mother liked the taste of the Broad Street water, they regularly supplied her with water from the pump—this time, with fatal results.
Hearing of this, and knowing that Mrs Lewis had been dumping contaminated water near the pump, he felt the trail getting warmer.
28. He Saw Something Else Brewing
Snow saw something unexpected in the nearby Lion Brewery. None of the brewery’s 70 workers had come down with cholera. In the utterly ravaged neighborhood, with workers toiling away at close quarters indoors, it seemed miraculous that the brewery was unscathed. Snow hungered for an explanation of the anomaly.
29. He Looked The Other Way At Their Drinking
Snow found out that the workers drank a company beer allowance each day instead of drinking water. Even more important, it turned out that the brewery’s water needs were such that they had dug their own well, and thus had a private supply of their own water separate from the Broad Street pump. That only deepened Snow’s suspicion.
30. He Found The Prime Suspect
In case after case, residents who had lost family members confided that they used the Broad Street pump as their primary source of drinking water. As Snow and the genial Whitehead heard more cases, they saw many of those afflicted had bypassed pumps closer to their home in order to get better-tasting water from the one in Broad Street. Snow zeroed in on the Broad Street pump.
31. He Put His Theory To The Test
Convinced that contaminated water from the pump was the source of the outbreak, Snow collected samples of its water. Snow hoped that close examination of the well-water under a microscope would lead to a definitive conclusion that the water was polluted. But he was surprised by what he saw in his slide.
32. He Couldn’t Find Hard Evidence
John Snow was an old hand with the microscope, but even his insightful investigations were unable to uncover definite evidence of contamination in the water. But Snow believed the pattern of occurrences still indicated that the Broad Street pump should be shut down.
He abandoned the stuffy confines of his lab and went straight to the neighborhood authorities.
33. He Explained The Problem
Snow approached the public works authority in the area and explained his findings, requesting that the Broad Street pump be shut down. Without a contaminated water sample in hand, he explained how almost all the deaths in the area were of people who regularly drank water from the pump; conversely, those unaffected had used different water pumps.
He prayed that his request hadn’t fallen on deaf ears.
34. He Shut It Down
John Snow was relieved to hear that the authority had agreed to have the pump shut down. The pump’s handle was removed on September 8, 1854. As cholera case numbers in the neighborhood declined, Snow was left to consider a new problem.
35. He Pondered A Conundrum
Though Snow was relieved that the pump was shut down, case numbers had decreased for the past few days due to most of the people having fled the area. The Broad Street water sample had tested negative, so Snow couldn’t be sure that the decrease wasn’t caused by a disappearance of the contaminant.
In the shadow of these ruminations, a new series of rumors was bubbling up.
36. He Heard A Competing Theory
Amid the horror of the outbreak, its origin became the subject of gruesome speculation by the locals. As this story went, excavations to expand the city sewer system had disturbed buried victims of the 1665 Bubonic Plague, unleashing the contagion that tormented the neighborhood. With public opinion in an uproar, the city authorities stepped in.
37. He Saw A Map
City Hall sent public works engineer John Cooper to investigate. Cooper did his own exhaustive research on the area, and with the help of city statistics, created a map that showed no correlation between cholera deaths and recent sewer excavations. The map quelled the hysteria, and encouraged Snow to pursue an idea of his own.
38. He Made His Own Map
Anxious to illustrate the results of his research, John Snow created a map of his own. He took a map of London and plotted two sets of points: cholera deaths; and the locations of pumps for drinking-water. The thick cluster of black dots surrounding the Broad Street pump made it obvious that it was at the center of the Soho outbreak. The map’s implications were clear. But would it convince the authorities?
39. He Made His Case
In his report on his findings, Snow explained that there was no particular outbreak of cholera in London other than in that small group that got their water from the Broad Street pump. But though Snow had explained the outbreak’s origin, it didn’t fully convince the public of the danger lurking in London’s drinking water. But he suddenly found further evidence in another part of the city.
40. He Rushed To A New Outbreak
The London district of Deptford had meanwhile suffered its own cholera rampage, with a familiar, devastating outcome: 90 people had perished. Snow quickly began gathering information in the community to piece together what had happened and recognized a familiar foe.
41. The Usual Suspect
It turned out that the Deptford victims had all been using the same pump for their drinking water, but reported that they recently had been letting the water run a bit longer to clear it of a of a foamy foul-smelling substance. None of the surrounding neighborhoods had lost anyone to cholera.
As with the Soho outbreak, John Snow surmised that the pump had been contaminated underground.
42. They Did A 180 On Him
Later in the month, the authorities in Soho had the handle reinstalled on the pump in Broad Street. They had never really bought into Snow’s explanation of the outbreak to begin with. Having half-heartedly gone along with his initial request, they now decided it was high time for the neighborhood to move on.
But the brooding Snow wasn’t even close to being done with the matter.
43. His Views Were Not For The Squeamish
Though sewage was regularly dumped into the Thames, large numbers of people relied on the river as a water source. Snow knew that people couldn’t visualize invisible germs polluting such a huge volume of water. And the thought that they were drinking filth was too much for the public to handle.
Snow would need a larger body of evidence to counter this psychological resistance.
44. He Wondered About The Source
John Snow knew that most houses in Soho used a cesspit for their waste. Residents often dumped waste into the river Thames in order not to overflow their household cesspit. With this unpleasant knowledge in mind, he returned his attention to a long-term project he’d been working on.
45. He Wanted A Bigger Picture
When the Soho outbreak hit, Snow had been working on a project about the companies supplying drinking water to the city’s residents. He was aware that some water companies drew their water from the Thames downstream of the main sewage discharge, and that some got water from upstream of the discharge. Picking up his project where he’d left off, he zeroed in on two water companies in particular.
46. He Wouldn’t Advise Drinking That
Snow knew that the Southwark and Vauxhall Waterworks was one of the biggest water suppliers in London. Water samples had been tested by the eminent Dr Hassell, who’d made a truly vile discovery. In the water, he’d found the unwelcome presence of animal hairs and other foul substances.
Critically, the plant lay downstream from the main sewage outfall on the Thames. Snow scanned the area for a suitable water plant to compare it with.
47. He Went Upstream
John Snow looked further up the Thames and chose the Seething Wells water plant, run by the Lambeth Water Company. This plant drew water from the Thames upstream from the sewage outfall, and even filtered their water. Snow now had two separate water plants to compare. But he still faced an even bigger challenge.
48. He Researched Who Was Drinking The Water
With a map of all the known cholera cases in London handy, Snow now set out on the daunting project of pinning down where all these people were getting their water from. He followed up by going to the houses of each of the cases individually. While engaged in this tedious legwork, he had a revelation.
49. He Saw A Pattern
John Snow discovered that the companies delivered their water through networks all through the city. People next door to each other could get water from a different company’s pipes; there was no class distinction or geographic pattern to the water use. It was a landmark observation.
50. He Performed A First
In effect, Snow was performing a double-blind experiment on the city’s water supply. He hadn’t set out to do so, but the pattern of water usage in the city had coincidentally provided him the conditions for the first true epidemiological study. Bu though his methodology was sound, he knew that results were what mattered.
51. He Ran More Tests
John Snow had a sample of tens of thousands of London residents to analyze. Where it was uncertain what company was supplying the water to a house, he had to conduct tests to infer which company it had come from. With all the additional statistical work, Snow was consumed with his project for months. But then the moment of truth arrived.
52. The Truth Hit Him
After he totaled up all the figures, Snow analyzed the results. Though he had expected to confirm his hypothesis that contaminated water had been the cause of the cholera specter haunting London, even he was amazed by the stark reality of what he was looking at.
53. He Proved It Beyond Doubt
Snow’s results showed that the rate of cholera fatalities in homes supplied by Southwark and Vauxhall was a whopping 14 times the rate of those supplied by the Lambeth works. Snow drew up his results in an 1855 paper called On the Mode of Communication of Cholera.
But his findings would echo far beyond the dusty halls of academia.
54. He Testified In Parliament
Snow’s results attracted the attention of the British government, who invited him to relay his findings to a parliamentary committee. He testified to the stark difference between the water quality of the two companies and its respective public health outcomes.
Galvanized by Snow’s work, the government made a momentous decision.
55. He Forced The System To Change
The government banned the collection of drinking water from anywhere downstream of Teddington, a township just downstream from Seething Wells. Snow’s work had resulted in a permanent change to the way things were done. But Snow couldn’t relax quite yet.
56. They Still Didn’t Believe Him
Though an increasing number of colleagues and officials saw the sense in Snow’s compelling research, he was fighting an uphill battle against the establishment. Many remained unconvinced. Editorials and letters in medical journals continued to advance the miasma theory, and ripped into Snow’s single-minded pursuit of his ideas.
But it was the miasma theory itself that would soon be put to the test.
57. He Held His Nose
In June of 1858, one of the biggest heat waves on record descended over southern England. The raw sewage in the Thames began to create an ungodly smell. With each passing day, the noxious stench wafted through the city, nauseating everyone and driving them indoors. No one had ever seen—or smelled—a miasma like it before.
But then something curious happened.
58. He Didn’t Hear Of Any Outbreak.
According to the miasma theory, the rancid odor that blanketed London should have triggered a massive outbreak of cholera. But revealingly, cholera case numbers barely budged all summer. The whole situation was a major argument against the miasma theory. But by mid-June, Snow was engaged in a far more serious matter.
59. He Was Struck Down
On June 10, 1858, while working in his office on a paper about anesthetics, John Snow suffered a stroke. He was bedridden for six days before passing on on June 16. While his obituary in the local medical journal credited Snow for his work with anesthesiology, there was no mention of his cholera research.
60. The Hazards Of His Occupation
After Snow’s passing, friends and colleagues came to a worrying conclusion. They couldn’t help but wonder whether the nature of his work had contributed to his premature demise. With the many surgeries he did and his constant experimentation with the volatile gases, it was easy to imagine the possible side effects on Snow.
But while some speculated on the causes of Snow’s demise, others continued to build on his discoveries.
61. He Didn’t Live To See The Progress
The terrible smell of the 1858 heat wave was what finally motivated London to build a massive new sewer system that would carry all the wastewater out beyond the tideline of the Thames. Soon afterward, Louis Pasteur and others discovered the germ theory of disease, putting the miasma theory in the dustbin of history.
Snow hadn’t lived to see the amazing progress but others began to advance his ideas.
62. His Colleagues Carried On In His Place
Dr Snow wasn’t renowned for his warm bedside manner; his strong views meant that his dealings with his professional colleagues were often highly contentious. But he had converted many of them to the water-borne disease theory by the strength of his arguments. One such colleague was Dr William Farr.
63. He Converted A Skeptic
Dr Farr was one of those who had rejected Snow’s early ideas on water-borne transmission. But after 1854, as the years went by, he gradually came to accept the truth of Snow’s findings. A rapidly approaching calamity would give Farr the chance to put Snow’s theories into practice.
64. His Ideas Were Further Proven
The biggest cholera outbreak in several years struck London in 1866. Using Snow’s model, Dr Farr compiled a report showing the source of contamination in a nearby reservoir. Dr Edwin Lankester, a longtime advocate of Snow’s views, had made the decision to shut down the local water pump, ending the outbreak.
It was the last cholera outbreak in London history, vindicating ideas Snow had held going back decades to his days as a young medical student.
65. He Watched What He Ate
At some point during his early studies John Snow read a pamphlet on the benefits of vegetarianism. He cut out meat from his diet; though he continued to eat eggs and dairy products; he began to drink water only if it was distilled. These convictions soon brought him into contact with other writings that made him extremely conscious of what he put into his body.
66. He Was A Teetotaler
Mistrustful of the purity of food and water sources, John soon began reading up on the dangers of drinking. He came across temperance movement pamphlet exhorting its readers to renounce alcohol altogether. From that day forth, John would not consume another drop. He also pursued an increasingly active lifestyle.
67. He Was Physically Active
To supplement his strict dietary habits, he took up swimming and eventually excelled in the aquatic pursuit. When Snow set off to London for medical school in 1835, he walked the entire 200 miles from York! This kind of physical vigor and stamina made him highly suitable for the medical profession and its long working hours.
68. He Was A Lifelong Bachelor
Even though Snow was a successful doctor who even had contacts with royalty, he remained a confirmed bachelor. His non-stop curiosity about scientific and medical matters pushed his social life to the side. But what he lacked in human companionship, he more than made up for with the magnitude of his work.
69. His Legacy Looms
Snow’s work continued to grow in influence long after he was gone. The simplicity and straightforwardness of the Broad Street map and his wider investigations was exactly what was needed to make progress toward the eventual eradication of cholera in Britain. As a result, many today regard Snow as the founding father of epidemiology.
The Broad Street pump still stands in Soho as a monument to the man who stopped cholera.
70. He Might Chuckle To See It
Not far from the Broad Street pump monument stands the John Snow Pub. Serving millions of pints since its 1870 founding, it hosts an upstairs section displaying several mementoes of Snow’s life and work. The teetotalling Snow would be surprised if he could see it!