The Ghost Map

by Steven Johnson

  Whether you looked at the evidence on the scale of an urban courtyard or on the scale of entire city neighborhoods, the same pattern repeated itself: the cholera seemed to segment itself around shared water supplies. If the miasma theory were right, why would it draw such arbitrary distinctions? Why would the cholera devastate one building but leave the one next door unscathed? Why would one slum suffer twice the losses as a slum with arguably worse sanitary conditions?

  Snow introduced his theory of cholera in two forms during the second half of 1849: first as a self-published thirty-one-page monograph, On the Mode and Communication of Cholera, intended for his immediate peers in the medical community, and then as an article in the London Medical Gazette, targeted at a slightly wider audience. Shortly after the publication, a country doctor named William Budd published an essay that came to similar conclusions about cholera’s waterborne transmission, though Budd left open the possibility that some cases of cholera might be transmitted through the atmosphere, and he claimed, erroneously, to have identified the cholera agent in the form of a fungus growing in contaminated water supplies. Budd would later make an observation regarding the waterborne transmission of typhoid, for which he is now best known. But Snow’s cholera theory had beaten Budd’s to the presses by a month, and it did not include the false lead of fungal agents or of atmospheric transmission.

  The reaction to Snow’s argument was positive but skeptical. “Dr. Snow deserves the thanks of the profession for endeavouring to solve the mystery of the communication of cholera,” a reviewer wrote in the London Medical Gazette. But Snow’s case studies had not convinced: “[They] furnish no proof whatever of the correctness of his views.” He had convincingly demonstrated that the South London neighborhoods were more at risk for cholera than the rest of the city, but it did not necessarily follow that the water in those neighborhoods was responsible for the disparity. Perhaps there was special toxicity to the air in those zones of the city that was absent in the slums to the north. Perhaps cholera was contagious, and thus the cluster of cases in South London simply reflected the chain of infection thus far; if the initial cases had unfolded differently, perhaps the East End would have been attacked more grievously, and South London left relatively unscathed. There was a correlation between water supply and cholera—that much Snow had convincingly proved. But he had not yet established a cause.

  The Gazette did suggest one scenario that might settle the matter convincingly:

  The experimentum crucis would be, that the water conveyed to a distant locality, where cholera had been hitherto unknown, produced the disease in all who used it, while those who did not use it, escaped.

  That passing suggestion stayed with Snow for five long years. As his anesthesia practice expanded, and his prominence grew, he continued to follow the details of each cholera outbreak, looking for a scenario that might help prove his theory. He probed, and studied, and waited. When word arrived of a terrible outbreak in Golden Square, not ten blocks from his new offices on Sackville Street, he was ready. So many casualties in such a short stretch of time suggested a central contaminated water source used by large numbers of people. He needed to get samples of the water while the epidemic was still at full force. And so he made the journey across Soho, into the belly of the beast.

  Snow’s expectation was that contaminated water would have a cloudiness to it that was visible to the naked eye. But his initial glance at the Broad Street water surprised him; it was almost entirely clear. He drew samples from the other pumps in the area: Warwick Street, Vigo Street, Brandle Lane, and Little Marlborough Street. All were murkier than the Broad Street water. The Little Marlborough Street sample was worst of all. As he drew the water there, a handful of local residents on the street remarked that the pump water was notoriously poor—so poor, in fact, that many of them had taken to walking the extra blocks to Broad Street for their drinking water.

  As Snow hurried back to his home on Sackville Street, he turned over the clues in his mind. Perhaps the Broad Street pump was not the culprit after all, given the lack of particles in the water. Perhaps one of the other pumps was the culprit? Or perhaps some other force was at work here? He would have a long night ahead of him, analyzing the samples, taking notes. He knew an outbreak of this magnitude could supply the linchpin for his argument. It was just a matter of finding the right evidence, and figuring out how to present that evidence in a way that would persuade the skeptics. Snow may well have been the only soul in Soho that day who found in the outbreak a glimmer of hope.

  Snow didn’t realize it at the time, but as he walked home that Sunday night, the basic pattern of that experimentum crucis suggested five years before in the London Medical Gazette was finally taking shape, miles away from Broad Street, in the greenery of Hampstead. Susannah Eley had fallen ill earlier in the week after drinking her regular supply of Broad Street water, dutifully shipped to her by her children in Soho. By Saturday she was dead, followed on Sunday by her niece, who had returned to her home in Islington after visiting with her aunt. As Snow reviewed the pump-water samples in his microscope, Susannah Eley’s servant, who had also consumed a glass of Broad Street water, remained locked in a life-or-death struggle with the disease.

  Not one other case of cholera in Hampstead would be recorded for weeks.

  IT’S ENTIRELY LIKELY THAT HENRY WHITEHEAD PASSED JOHN Snow on the streets of Soho that early evening. The young curate had toiled through another exhausting day, and was still making rounds well after the sun had set. Whitehead had begun the day with a feeling of hope; the fact that the streets seemed less chaotic made him wonder whether the outbreak was abating. A few of his initial visits offered reason for hope as well: the Waterstone girl had improved, and her father, having lost an otherwise perfectly healthy wife and daughter in less than two days’ time, had begun consoling himself with the thought that life indeed might be worth living if his one remaining daughter somehow survived. Whitehead shared his upbeat assessment with a few of his colleagues on the sidewalk, and found some agreement.

  But the quiet proved misleading: the streets were more tranquil because so much suffering was going on behind the shutters. In the end, another fifty would die over the course of the day. And new cases continued to appear at an alarming clip. When Whitehead returned to the Waterstones’ at the end of the day, he found the sister continuing her improvement. But in the room next door, the girl’s father was in the throes of cholera’s initial attack. Life might well be worth living if his daughter survived, but the decision might not be up to him after all.

  When Whitehead finally returned to his quarters at the end of that punishing day, he poured a glass of brandy and water, and found himself thinking of the Waterstones’ ground-floor quarters. He had encountered the gossip that had been circulating in the past day, folk wisdom that would eventually find its way into the papers in the coming weeks: the residents of upper floors were dying at a more dramatic rate than those living on ground or parlor floors. There was a socioeconomic edge to this contention, one that reverses the traditional upstairs/downstairs division of labor: in Soho at the time, the bottom floors were more likely to be occupied by owners, with the upper floors rented out to the working poor. An increased death rate in the upper floors would suggest a fatal vulnerability in the constitution or sanitary habits of the poor. The notion, in its crude and haphazard way, was a version of Snow’s tale of two buildings in Horsleydown: put two groups of people in close proximity, and if one group turns out to be significantly more vulnerable than the other, then some additional variable must be at work. For Snow, of course, the variable was water supply. But for the upstairs/downstairs rumor mill, the difference was class. A better sort of people lived on the ground floors—no wonder they were more likely to fight off the disease.

  But as Whitehead reviewed his experiences over the preceding days, those easy assumptions began to wither in his mind. Yes, it did seem as though more people were dying on upper floors, but far more people lived on u
pper floors. And the Waterstones were clear evidence that the disease could assault ground-floor dwellers with impunity. Whitehead didn’t have numbers in front of him, but he had a hunch from his anecdotal experiences that the lower floors had in fact been deadlier per capita over the previous forty-eight hours. It was certainly a fact worth investigating—if the pestilence ever moved on from Golden Square long enough to investigate anything.

  Fifteen blocks away, on Sackville Street, John Snow was contemplating statistics as well. He had already sketched out a plan to ask William Farr for an early look at the mortality numbers. Perhaps there would be something in the distribution of deaths that would point to a contaminated water supply. Like Whitehead, Snow recognized that his work among the suffering of Golden Square had only begun. Whatever numbers William Farr provided him would have to be supplemented with local investigation. The longer he waited, the more difficult that investigation would become, if only because so many of the witnesses were dying.

  Snow and Whitehead shared one other common experience that night. They both spent those last ruminating hours in the company of water drawn from the Broad Street pump. Snow was analyzing it in his home laboratory, his vision dimmed by the low light of candles. The young curate, however, had used the water in a different way, more recreational than empirical: he had mixed the water with a thimble of brandy and swallowed it.

  WILLIAM FARR

  Monday, September 4

  THAT IS TO SAY, JO HAS NOT YET DIED

  THE BRIGHT LATE-SUMMER SUN THAT ROSE OVER LONDON that Monday revealed a ghost town in the streets around Golden Square. Most who hadn’t fallen ill, or who weren’t tending to the fallen, had fled. Many of the storefronts remained closed for the day. A terrible gloom hovered over the Eley Brothers factory: more than two dozen laborers had been seized with the cholera, and news had arrived of Susannah Eley’s death. (Little did the Eley brothers realize that their devotion to their mother had been instrumental in her demise.) The wife of Mr. G—the tailor who had been among the first to succumb—had herself collapsed the night before.

  A few odd islands appeared in this sea of devastation. At the Lion Brewery, a hundred feet down Broad Street from the pump, work continued with a strange semblance of normalcy. Not one of the eighty laborers there had perished yet. The cholera continued to spare the tenements of Green’s Court, despite their filthy, overcrowded quarters. Among the five hundred destitute residents at the St. James Workhouse on Poland Street, only a handful had come down with the disease, while the comparatively well-to-do houses that surrounded it had lost half their inhabitants in the space of three days.

  But every time the Reverend Whitehead thought he saw reason for hope, another tragedy would arrive to dampen his natural optimism. When he returned to the Waterstones on Monday, he found that the lively, intelligent daughter he had long admired—whose health had taken a turn for the better the day before—had suffered a sudden relapse and died during the night. The few remaining family members were attempting to conceal the death from the girl’s father, who continued his own struggle with the disease.

  Whitehead began to hear talk spreading among his parishioners blaming the outbreak on the new sewers that had been constructed in recent years. The residents were whispering that the excavations had disturbed the corpses buried there during the Great Plague of 1665, releasing infectious miasma into the neighborhood’s air. It was a kind of haunting, couched in the language of pseudoscience: the dead of one era’s epidemic returning, centuries later, to destroy the settlers who had dared erect homes above their graves. The irony was that the terrified residents of Golden Square had it half right: those new sewers were in fact partly responsible for the outbreak that was devastating the city. But not because the sewers had disturbed a three-hundred-year-old graveyard. The sewers were killing people because of what they did to the water, not the air.

  Other distortions and half-truths circulated between the neighborhood and the wider city. The folklore spread in part because the communication system of London in the middle of the nineteenth century was a strange mix of speed and sluggishness. The postal service was famously efficient, closer to e-mail than the appropriately nicknamed “snail mail” of today; a letter posted at nine a.m. would reliably find its way to its recipient across town by noon. (The papers of the day were filled with aggrieved letters to the editor complaining about a mailing that took all of six hours to find its destination.) But if person-to-person communication was shockingly swift, mass communication was less reliable. Newspapers were the only source of daily information about the wider state of the city, but for some reason the Broad Street outbreak went unmentioned for nearly four days in the city’s main papers. One of the very first reports appeared in the weekly paper the Observer, though it greatly underestimated the magnitude of the attack: “It is said that Friday night will long be remembered by the inhabitants of Silver-street and Berwick-street. Seven persons were in good health on Friday night, and on Saturday morning they were all dead. Throughout the night people were running here and there for medical aid. It seemed as if the whole neighbourhood was completely poisoned.”

  With the newspapers largely silent on the topic, word of the terrible plague in Soho trickled out through the amplifying networks of gossip. Rumors began circulating that the entire neighborhood had been wiped out, that some new strain of cholera was killing people within minutes, that the dead were lying uncollected in the streets. More than a few Golden Square residents who worked outside the area left because their employers demanded they abandon their homes immediately.

  The information channels were unreliable in both directions. In the belly of the beast, the terrified citizens of Soho traded stories: that the epidemic had struck Greater London with equal ferocity; that hundreds of thousands were dying; that the hospitals were overloaded beyond imagination.

  But not all the locals had succumbed to abject fear. As he made his rounds, Whitehead found himself musing on an old saying that invariably surfaced during plague times: “Whilst pestilence slays its thousands, fear slays its tens of thousands.” But if cowardice somehow made one more vulnerable to the ravages of the disease, Whitehead had seen no evidence of it. “The brave and the timid [were] indiscriminately dying and indiscriminately surviving,” he would later write. For every terrified soul who fell victim to the cholera, there was another equally frightened survivor.

  Fear might not have been a contributing factor in the spread of disease, but it had long been a defining emotion of urban life. Cities often began as an attempt to ward off outside threats—fortified by walls, protected by guards—but as they grew in size, they developed their own, internal dangers: disease, crime, fire, along with the “soft” dangers of moral decline, as many believed. Death was omnipresent, particularly for the working class. One study of mortality rates from 1842 had found that the average “gentleman” died at forty-five, while the average tradesman died in his mid-twenties. The laboring classes fared even worse: in Bethnal Green, the average life expectancy for the working poor was sixteen years. These numbers are so shockingly low because life was especially deadly for young children. The 1842 study found that 62 percent of all recorded deaths were of children under five. And yet despite this alarming mortality rate, the population was expanding at an extraordinary clip. Both the burial grounds and the streets were filling up with children. That contradictory reality explains, in part, the centrality of children in the Victorian novel, particularly in Dickens. There was, for the Victorians, something singularly charged about the idea of innocent children being exposed to the diseased squalor of the city, a notion that is, interestingly, almost entirely absent from French novels of the same period. When Dickens introduces the vagabond child Jo in Bleak House, his language implicitly references the dismal child-mortality statistics of the day: “Jo lives—that is to say, Jo has not yet died—in a ruinous place known to the like of him by the name of Tom-all-Alone’s. It is a black, dilapidated street, avoided by all decent peopl
e, where the crazy houses were seized upon, when their decay was far advanced, by some bold vagrants who after establishing their own possession took to letting them out in lodgings.” The phrasing captures the dark reality of urban poverty: to live in such a world was to live with the shadow of death hovering over your shoulder at every moment. To live was to be not dead yet.

  From our vantage point, more than a century later, it is hard to tell how heavily that fear weighed upon the minds of individual Victorians. As a matter of practical reality, the threat of sudden devastation—your entire extended family wiped out in a matter of days—was far more immediate than the terror threats of today. At the height of a nineteenth-century cholera outbreak, a thousand Londoners would often die of the disease in a matter of weeks—out of a population that was a quarter the size of modern New York. Imagine the terror and panic if a biological attack killed four thousand otherwise healthy New Yorkers over a twenty-day period. Living amid cholera in 1854 was like living in a world where urban tragedies on that scale happened week after week, year after year. A world where it was not at all out of the ordinary for an entire family to die in the space of forty-eight hours, children suffering alone in the arsenic-lit dark next to the corpses of their parents.