Get the number of cases in each house, and the number of deaths of persons who lived in each house.
Examine the water supply as to its source, quality, amount, whether drawn from pipes or water-butts, and the condition of the butts.
Note the general condition of the streets and courts, and inquire what was the state of the cleansing before the outbreak.
Examine whether the disturbance of the ground in making a sewer through the old burial ground in Little Marlborough Street, or the filtrations from it into the sewer, or the drainage of any nuisance into the general sewerage of the district had had any effect, or whether the sewers had accumulations in them that might have been injurious.
Hall’s instructions for his cholera committee offer a brilliant case study in how dominant intellectual paradigms can make it more difficult for the truth to be established, even if the people involved are smart and attentive and methodical in their research. Hall’s list is a kind of straitjacket for an eventual document. You can tell from just scanning the instructions what kind of document they will ultimately produce: a rich and impossibly detailed inventory of the smells of Soho circa 1854. Half of the categories specifically mention smell and ventilation, and the few directives that might potentially be relevant to the waterborne theory of the disease—such as the condition of the cesspools—are specifically colored by Hall’s concern about smell in each instance.
In all, Benjamin Hall delivered about fifty specific instructions to his committee. Only two of them—regarding the quality and source of the water supply—were essential to proving or disproving Snow’s waterborne theory. But of course, on their own, those two variables were close to meaningless. Snow himself had detected nothing unusual in the water on Monday morning, at the height of the epidemic. Analyzing the quality of the water using the available technologies of the day couldn’t shed light on the mystery either way: there was nothing to see. Pacini had caught a glimpse of the bacteria in his microscope that year, but he would be alone in his discovery for three decades. The most reliable way to “see” the cholera was indirectly, in the way the drinking habits of the neighborhood mapped onto the patterns of disease and death that Farr had captured in the Weekly Returns. If you failed to superimpose those two data sets, the power and clarity of the waterborne theory disappeared. But Hall never asked his committee to investigate the drinking habits of the population, much less compare those habits to the overall distribution of deaths.
It’s crucial to note that Hall was not blind to the basic epidemiological principles that governed Snow’s work—that the cause of a disease can be deduced by observing statistically unusual patterns in the course of an epidemic. Hall requested that the investigators report on whether the cholera deaths were concentrated around gully gates or the site of the plague burial ground. But the waterborne theory did not rise to that level of scrutiny. Despite the fact that Snow had published on the subject, and despite Snow’s numerous conversations with William Farr about cholera and the water supply, the president of the Board of Health did not find it necessary to determine whether there was an unusual concentration of deaths around any of the neighborhood’s sources of drinking water. Hall’s instructions had rigged the game against Snow’s theory from the very outset.
But Hall’s task force would not be the only one investigating the Broad Street epidemic. In the weeks and months that followed the outbreak, another group would probe the neighborhood, piecing together the story, looking for clues. And at its center would be the one man who probably knew the neighborhood as intimately as anyone in Soho: Henry Whitehead.
NEWS OF THE PUMP HANDLE’S REMOVAL HAD STRUCK WHITEHEAD as being particularly foolish. When he first heard the contaminated-pump theory that Friday, he reacted with a quick dismissal, siding with the jeering throngs on Broad Street. This will be easy enough to disprove, he thought. And Whitehead was uniquely equipped to do the disproving. Snow’s two-day investigation couldn’t compete with the bedside hours Whitehead had logged since the outbreak first erupted on Friday. The young curate had already been constructing arguments against other prevailing theories. Now he would add the waterborne theory to the list. The Board of Governers might have been easily swayed by Dr. Snow’s demographic sleight of hand, but they didn’t know the neighborhood as well as Whitehead did; they hadn’t seen a girl drink seventeen quarts of pump water and survive. It would take some additional research, Whitehead knew, but he was confident that the pump would be exonerated in time.
“Every limit is a beginning as well as an ending,” George Eliot would write a few years later in Middlemarch. So it is with the story of the pump handle’s removal. It was the end of the Broad Street well’s assault on Golden Square, and the beginning of a new era of public health. But it does not offer the easy closure of the detective story. The remaining residents did not gather around Dr. Snow to celebrate his solving the mystery of Broad Street; Benjamin Hall did not drop his miasma obsessions overnight; even the Board of Governers remained unimpressed with Snow’s theory, though they followed his advice. And Henry Whitehead was so unconvinced by the case against the pump that he vowed to disprove it. So the true narrative arc of the Broad Street outbreak turns out to have a dialectical twist at its end: in persuading the otherwise incompetent Board of Governers to follow his advice, Snow awakened the one adversary who possessed more local knowledge of the outbreak than himself. In overcoming one opponent, Snow created an even more daunting challenge for his waterborne theory. Snow still had a long list of potential converts to win over: Benjamin Hall and his miasma-addled investigators; William Farr; the editors of The Lancet. But in the short term, his primary nemesis would be the Reverend Henry Whitehead.
WHITEHEAD HAD BEEN INFORMALLY ASSEMBLING CLUES FROM the very outset. On that Friday, before receiving word of the pump handle’s removal, he had ascended to the pulpit at St. Luke’s to give the daily sermon. Standing in front of his haggard parishioners in the half-empty church, he noted the disproportionate number of poor, elderly women in the pews. He congratulated them on their “remarkable immunity from the pestilence.” But even as he spoke the words, he wondered: How can this be? What kind of pestilence spares the old and the destitute?
In the months that followed, Whitehead and Snow explored Broad Street on separate but parallel tracks. Snow began integrating the data from his investigation into a new version of his cholera monograph from 1849, while writing a handful of articles for the medical journals that addressed the outbreak. The section of the monograph devoted to Broad Street began with these dramatic lines:
The most terrible outbreak of cholera which ever occurred in this kingdom, is probably that which took place in Broad Street, Golden Square, and the adjoining streets, a few weeks ago. Within two hundred and fifty yards of the spot where Cambridge Street joins Broad Street, there were upwards of five hundred fatal attacks of cholera in ten days. The mortality in this limited area probably equals any that was ever caused in this country, even by the plague; and it was much more sudden, as the greater number of cases terminated in a few hours. The mortality would undoubtedly have been much greater had it not been for the flight of the population. Persons in furnished lodgings left first, then other lodgers went away, leaving their furniture to be sent for when they could meet with a place to put it in. Many houses were closed altogether, owing to the death of the proprietors; and, in a great number of instances, the tradesmen who remained had sent away their families: so that in less than six days from the commencement of the outbreak, the most afflicted streets were deserted by more than three-quarters of their inhabitants.
That fall, Whitehead quickly wrote and published a seventeen-page monograph titled The Cholera in Berwick Street. It was the first comprehensive look at the outbreak written for a general audience. Most of Whitehead’s inquiries over those initial weeks were aimed at taking stock of the outbreak’s reach and its duration. He began his monograph with a terse inventory:
Dufour’s Place.—Houses, 9; population 170; deaths,
9; houses without any deaths, 4. Rumour sadly exaggerated the mortality in this place.
Cambridge Street.—Houses, 14; population, 179; deaths, 16; deaths on the west side, 10; east, 6, of which 3 were in one house. Five houses escaped.
Whitehead described the strange lack of connection he had observed at the height of the outbreak between the sanitary conditions and the mortality rates in each residence. He noted that the model home on Peter Street—the very one that had been commended by the authorities several years back for its cleanliness—had suffered twelve deaths, the largest number of any residence in the neighborhood. He traced the devastation that the outbreak had leveled against the neighborhood’s families: “There were no less than 21 instances of husband and wife dying within a few days of each other. In one case, besides parents, 4 children also died. In another both parents and 3 of their 4 children. In another, a widow and 3 of her children.” Not fifteen yards from the front steps of St. Luke’s Church stood four houses that had, between them, lost thirty-three people.
Reading Whitehead’s monograph, you can sense the young curate grappling with the theological implications of the outbreak. A visitation of plague had to be, on some level, an expression of divine will, and in this case the divinity appeared to have singled out the parish of St. Luke’s for the most severe retribution imaginable. It must have been a vexing reality to face as a man of the cloth: of all the parishes in London, over the many years that cholera had ravaged the country, God had seen fit to subject Whitehead’s own small community to the most explosive epidemic attack in the history of the city. In the monograph, Whitehead initially professes an inability to explain such an event in terms of divine will, but then he offers a half-formed theory, one that itself follows a markedly dialectical logic:
God’s ways are equal, man’s ways are unequal; and another fact, less difficult to be accounted for, presents itself to our notice, even the unequal accumulation of filth and dirt, the overcrowding together of human beings, the culpable sufferance of ill-constructed streets and ill-ventilated houses, indifference to first principles of drainage and sewage, aggravating the pestilence in particular localities, but attracting little attention and exciting little alarm, till here and there a mine explodes, revealing to the startled population of an ill-managed city the peril of a position which admits of any one street or parish, and that none of the lowest and filthiest, becoming a huge charnel house in a day or an hour.
Till here and there a mine explodes. The outbreak, as brutal as it was, nonetheless shed light on the poverty and despair of inner-city life, illuminating everyday suffering with the bright light of extraordinary despair. Whitehead had the story half right: the terrifying visibility of the outbreak did in fact sow the seeds of a cure. But it was not divine providence that drove the process. It was density. Crowd a thousand people into three city blocks and you create an environment where epidemic disease will flourish; but in flourishing, the disease reveals the telltale characteristics of its true nature. Its efflorescence points the way to its ultimate defeat. The Broad Street pump was a kind of urban antenna, sending out a signal through the surrounding neighborhood, a signal with a detectible pattern that allowed humans to “see” V. cholerae without the aid of microscopes. But without those thousand bodies crowded around the pump, the signal would have been lost, like a sound wave dissipating into silence in the vacuum of space.
In the weeks after the outbreak, Whitehead had observed enough of these patterns to debunk a number of prevailing theories in his monograph. His account of the devastation at Peter Street exposed the fallacy of the sanitary hypothesis; and he offered numerous cases of brave parishioners falling ill to combat the “fear kills” platitudes. He tabulated the ratio of deaths on upper and lower floors to demonstrate that the cholera had attacked both classes evenly. But despite his initial derision at the the pump handle’s removal, the Broad Street well goes unmentioned in the monograph. Perhaps Whitehead simply felt he hadn’t accumulated enough evidence against Snow’s case to include the waterborne theory in the text. Or perhaps his early inquiries had started to change his mind.
Either way, the monograph was only the beginning. Whitehead would end up pursuing details of the Broad Street outbreak further than he ever imagined in the coming months—further, indeed, than John Snow himself would venture. In late November, the vestry of St. James’ voted to form a committee to investigate the Broad Street outbreak, initially planning to produce a report based on a questionnaire circulated through the neighborhood, augmented by the data assembled by the Board of Health committee. But when the vestry approached Benjamin Hall, the Board’s president declined to share his committee’s findings—“principally on the ground that investigations of this kind were more valuable when independent.” The snub turned out to be fortuitous. Faced with limited returns from their questionnaire, and with no contribution from the Board of Health, the vestry recognized that they would have to assemble a team of their own investigators. On the merits of his recently published monograph, and recognizing the value of his knowledge of the community, they asked the Reverend Whitehead to join the committee. They also invited that local doctor who had been so agitated about the state of the Broad Street pump. Snow and Whitehead may not have agreed on the cause of the outbreak, but they were now working on the same team.
WHITEHEAD BEGAN HIS ASSAULT ON THE PUMP-CONTAMINATION theory by examining a crucial absence in Snow’s original survey of the neighborhood. Snow had focused almost exclusively on the Soho residents who had perished in the outbreak, detecting that an overwhelming majority of them had consumed Broad Street water before falling ill. But Snow had not investigated the drinking habits of the neighborhood residents who had survived the epidemic. If that group turned out to have drunk from the Broad Street pump at the same rate, then the whole basis for Snow’s theory would dissolve. The connection between pump drinking and cholera would be meaningless if most of the neighborhood—the dead and the living—were drinking from the pump. Most of the dead had probably also strolled down Broad Street at some point in the days leading up to the epidemic, but that didn’t mean that strolling down Broad Street caused cholera.
Whitehead’s local knowledge gave him a crucial edge in this investigation, in that he was uniquely able to track down the hundreds of residents who had fled the neighborhood in the weeks after the outbreak. Snow would have intuitively understood the importance of surveying the pump-drinking rates among the survivors, but the great majority of the survivors were unreachable to him that first week of September. And so Snow had been forced to build his case against the pump on his survey of the dead, augmented by a few odd cases of unlikely survival (the workhouse, the brewery). Whitehead, on the other hand, could draw upon the extensive social network he’d long ago established in the neighborhood to track down the émigrés from Golden Square. His investigation took him throughout the Greater London area in the months that followed his appointment to the committee; when he learned of former residents who had moved outside the city, he sent inquiries by post. In the end, he tracked down information on 497 residents of Broad Street, more than half the population that had lived there in the weeks before the outbreak.
As he threw himself into the investigation, sometimes visiting the same flat five separate times to pursue new leads, Whitehead felt his resistance to the pump-contamination theory fade. Again and again, the recollections of cholera survivors would eventually turn up some forgotten connection to the Broad Street pump. A young widow whose husband died on the first had originally told Whitehead that the couple had not been Broad Street drinkers. But several days later, a memory came back to her: on the night of the thirtieth her husband had asked her to fetch some water from the pump to drink with dinner. She herself had not consumed any. One woman whose husband and daughter had come down with the cholera (eventually surviving it), denied forthrightly that anyone in the house had ever favored the Broad Street water. But when she relayed the details of her curious interview with the
Reverend Whitehead to the rest of the family, the daughter recalled that, no, she had in fact drunk from the Broad Street well in the days before the outbreak.
This last case was typical of the stories that Whitehead unraveled: the children turned out to offer the missing link to the pump. In performing his analysis of the neighborhood’s drinking customs, Whitehead noted how often the young people were asked to fetch water for their families. A visit to the Broad Street pump was a commonplace chore for any child over the age of six or seven, and their familiarity with the well meant that a number of neighborhood children had drunk from it without their parents’ knowing. As he listened to these accounts, Whitehead’s mind returned to the image of all those widows gathered at St. Luke’s on the day the pump handle was removed. At last he had a potential explanation for their immunity. It wasn’t that the ladies were somehow morally superior to the dead; it wasn’t that they possessed sturdier constitutions or more hygienic lifestyles. What united them all as a group was that they were old and infirm and living alone, with the result that they didn’t have anyone to fetch water for them.
As Whitehead tabulated his initial numbers, the case against the pump looked powerful indeed. Among the pump-water-drinking population, the rates of infection were along the lines that Snow had outlined in his original survey: for every two Broad Street drinkers who were not affected, there were three who fell ill. That ratio seemed even more striking when you compared it to the infection rates among those who had not drunk from the well: only one in ten of that group had been seized with the cholera. As much as he had resisted the waterborne theory, Whitehead found himself confronting the stubborn fact that choosing to drink from the well increased your odds of infection sevenfold.
The Ghost Map: The Story of London's Most Terrifying Epidemic--and How It Changed Science, Cities, and the Modern World Page 16