Source: Cricket 31(3), pp. 23-31, Nov. 2003

Reprinted by permission of the author and Cricket Magazine, November 2003; text (c) 2003 by Kathleen Tuthill, artwork (c) 2003 by Carus Publishing Company.





By Kathleen Tuthill, Illustrated by Rupert Van Wyk


Dr. Snow, an obstetrician with an interest in many aspects of medical science, had long believed that water contaminated by sewage was the cause of cholera. Cholera is an intestinal disease than can cause death within hours after the first symptoms of vomiting or diarrhea. Snow published an article in 1849 outlining his theory, but doctors and scientists thought he was on the wrong track and stuck with the popular belief of the time that cholera was caused by breathing vapors or a “miasma in the atmosphere”.

The first cases of cholera in England were reported in1831, about the time Dr. Snow as finishing up his medical studies at the age of  eighteen. Between 1831 and 1854, tens of thousands of people in England died of cholera.  Although Dr. Snow was deeply involved in experiments using a new technique, known as anesthesia, to deliver babies, he was also fascinated with researching his theory on how cholera spread.

In the middle 1800s, people didn’t have running water or modern toilets in their homes. They used town wells and communal pumps to get the water they used for drinking, cooking and washing.  Septic systems were primitive and most homes and businesses dumped untreated sewage and animal waste directly into the Thames River or into open pits called “cesspools”.  Water companies often bottled water from the Thames and delivered it to pubs, breweries and other businesses.





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Besides those who lived near the pump, Snow tracked hundreds of cases of cholera to nearby schools, restaurants, businesses and pubs.

According to Snow’s records, the keeper of one coffee shop in the neighborhood who served glasses of water from the Broad Street pump along with meals said she knew of nine of her customers who had contracted cholera.

A popular bubbly drink of the time was called “sherbet”, which was a spoonful of powder that fizzed when mixed with water. In the Broad Street area of Soho, that water usually came from the Broad Street pump and was, Snow believed, the source for many cases.

Snow also investigated groups of people who did not get cholera and tracked down whether they drank pump water. That information was important because it helped Snow rule out other possible sources of the epidemic besides pump water. 

He found several important examples.  A workhouse, or prison, near Soho had 535 inmates but almost no cases of cholera.  Snow discovered the workhouse had its own well and bought water from the Grand Junction Water Works.

The men who worked in a brewery on Broad Street which made malt liquor also escaped getting cholera.  The proprietor of the brewery, Mr. Huggins, told Snow that the men drank the liquor they made or water from the brewery’s own well and not water from the Broad Street pump. None of the men contracted cholera. A factory near the pump, at 37 Broad Street, wasn’t so lucky. The factory kept two tubs of water from the pump on hand for employees to drink and 16 of the workers died from cholera. 

The cases of two women, a niece and her aunt, who died of cholera puzzled Snow.  The aunt lived some distance from Soho, as did her niece, and Snow could make no connection to the pump. The mystery was cleared up when he talked to the woman’s son. He told Snow that his mother had lived in the Broad Street area at one time and liked the taste of the water from the pump so much that she had bottles of it brought to her regularly. Water drawn from the pump on 31 August, the day of the outbreak, was delivered to her. As was her custom, she and her visiting niece took a glass of the pump water for refreshment, and according to Snow’s records, both died of cholera the following day.



Despite the success of Snow’s theory in stemming the cholera epidemic in Soho, public officials still thought his hypothesis was nonsense. They refused to do anything to clean up the cesspools and sewers. The Board of Health issued a report that said, “we see no reason to adopt this belief” and shrugged off Snow’s evidence as mere “suggestions.”

For months afterward Snow continued to track every case of cholera from the 1854 Soho outbreak and traced almost all of them back to the pump, including a cabinetmaker who was passing through the area and children who lived closer to other pumps but walked by the Broad Street pump on their way to school. What he couldn’t prove was where the contamination came from in the first place.


The mystery might never have been solved except that a minister, Reverend Henry Whitehead, took on the task of proving Snow wrong. The minister contended that the outbreak was caused not by tainted water, but by God’s divine intervention.  He did not find any such proof and in fact, his published report confirms Snow’s findings. Best of all, it gave Snow the probable solution to the cause of the pump’s contamination.

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The World Health Organization estimates 78 percent of the people in Third World countries are still without clean water supplies today, and up to 85 percent of those people don’t live in areas with adequate sewage treatment, making cholera outbreaks an ongoing concern in some parts of the world.

Today, scientists consider Snow to be the pioneer of public health research in a field known as epidemiology.  Much of the current epidemiological research done at the U.S. Centers for Disease Control, which still uses theories such as Snows’ to track the sources and causes of many diseases. 

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