The Ghost Map

By Monday, September 4, Soho was becoming a ghost town. The Eley Brothers factory was almost abandoned—most of its workers had taken ill, as had Susannah Eley. But at the Lion Brewery, just a few hundred feet away from the Broad Street Pump, not one person had contracted cholera.

On Monday, Whitehead visited the Waterstone family again, only to find that their daughter had died in the night. Meanwhile, the Waterstone patriarch was slowly dying of cholera, too. Some superstitious residents believed that the construction of a new sewer system had disturbed the corpses of ancient plague victims, buried underneath the ground. These people were half-right—the sewer system was responsible, but not because it had disturbed corpses. Rumors about the outbreak spread through London, yet newspapers were mostly silent on the topic.

Fear consumed London—and, in a way, fear had been the defining emotion of working-class Londoners for a long time. Studies have found that, in 1842, the average gentleman died at forty-five, while the average “tradesman” (i.e., typical working-class man) died in his mid-twenties. In other parts of England, the average working-class man died around the age of sixteen. This was so largely because of the high infant mortality rate; in the mid-19th century, the majority of all recorded deaths were of children under five. Death was everywhere in Victorian society, to a degree that many contemporary people probably can’t understood.

Throughout the 19th century, people lived in fear of disease, yet they had almost no idea how disease spread. The miasma theory—i.e., that there were specific places and odors that fostered the spread of disease—was still popular, in spite of Snow’s research. Clergymen like Whitehead, meanwhile, clung to their religious faith in times of cholera epidemics. Over the course of a lifetime, many Londoners became numb to the news of cholera outbreaks—they learned how to live normal lives with the threat of death hanging over their heads.

Seen through a Marxist lens, London in the 19th century was engaged in a vast dialectic (a clash or tension between an idea and its opposite, usually on an epochal or historical scale), as the “thesis” of progress and civilization was rapidly confronting its “antithesis”—disease, squalidness, and misery. London was the center of England, the most powerful country in the world; it was a hub of industry, finance, and intellectual life. And yet there were many thinkers who argued that London would collapse on itself, like Rome, Babylon, and other great cities of history. London was, after all, unprecedented in human history—never before had millions of people been packed into a thirty-three mile circumference. Lurking beneath people’s fears about cholera was an even more basic fear—the fear that the metropolis itself was an inherently doomed idea.

If London was such a miserable place to live, one might ask, then why were people clamoring to live there? While there were plenty of good answers to this question—economic opportunities, family, intellectual life, school—many people thought of the city of London as having taken on a life of its own. London expanded during the 19th century because of innovations in the flow of energy accompanying the Industrial Revolution. After the 1750s, London became a center of steam and coal energy; thus, one could argue, London became a sprawling metropolis not so much because individual people chose to live there, but because of the spike in available energy. The physicist and urban theorist Arthur Iberall argued that human organizations are analogous to different states of matter: over time, humans have moved from a hunter-gatherer (gaseous) stage to “the crystalline density of the walled city.”

But the upsurge in available energy cannot, by itself, explain the growth of London’s population. London grew in part because there was a sudden spike in the population, specifically the population of people willing to change locations. Surprisingly, one can trace this population explosion back to tea. In the 18th century, tea became the most common British drink. With its medicinal properties and—crucially—sterilized water, tea may have prolonged the average Englander’s life, thereby “supplying a larger labor pool to the emerging factory towns.”

Cities are life’s “largest footprint,” and bacteria are its smallest. And yet in Victorian London, these two extreme specimens of life were locked in combat, almost as if they were keeping each other in check. In 1854, epidemiology was still in its infancy—Victorians weren’t accustomed to conceiving of their cities as complex systems, and therefore they had a hard time conceiving of the ways that diseases spread. Cholera, John Snow quickly found, couldn’t be studied in isolation: it had to be seen from a “bird’s eye view.”

On Monday, John Snow was busy trying to find a “wider perspective” for the study of cholera. Around the same time, Florentine scientists had isolated the Vibrio cholera bacterium, a milestone for the germ theory of disease. However, the scientists’ papers on the subject were ignored for the next three decades. Meanwhile, in the absence of conclusive evidence for the existence of a cholera bacterium, Snow collaborated with the demographer William Farr. Farr was a scientist, but he still clung to the miasma theory; he thought that cholera was caused by putrid fog emanating from London’s riverbanks. However, Farr was open-minded enough to record information about cholera victims’ water supplies, recognizing that Snow’s theory might be correct.

Throughout history, human beings have struggled to find clean water. The invention of alcohol was crucial to human history, because (unbeknownst to anyone before the 19th century), the brewing process sterilized the water, rendering the drink potable. It’s been suggested that modern humans are better at “holding their liquor” than people who lived thousands of years ago, because holding one’s liquor is a major evolutionary advantage—people who can drink a lot have access to a bacteria-free supply of liquids.

In the 19th century, water was becoming a staple of the urban European’s diet, to an unprecedented degree. Wealthy 18th century Londoners had built private water pipe systems to provide themselves with clean water from streams outside the city; however, by the 19th century, water pipe companies had consolidated in major firms that designed piping systems for the whole city. When researching the spread of cholera in the late 1840s, Snow discovered that the people dying of cholera lived in a district of London whose piping needs fell under the domain of two firms, S&V and Lambeth. Snow realized that he had an opportunity to prove his theory: if he could show that cholera deaths in Soho correlated with one piping firm or the other, he would have strong evidence that cholera was waterborne, reinforcing the contagion theory.

Leading up to the cholera outbreak of 1854, John Snow had been visiting the Soho slums and inquiring about cholera victims’ water supplies. He visited hundreds of households, collecting water samples from each house’s tap. Since one piping firm used more salt than the other, it was easy to test which water came from which pipes. In the middle of his investigation, news broke of the new cholera outbreak. Snow realized that the outbreak might give him another opportunity to strengthen his research.