The Ghost Map: The Story of London's Most Terrifying Epidemic--and How It Changed Science, Cities, and the Modern World

by Steven Johnson

It is August 1854, and London is a city of scavengers. Just the names alone read now like some kind of exotic zoological catalogue: bone-pickers, rag-gatherers, pure-finders, dredgermen, mud-larks, sewer-hunters, dustmen, night-soil men, bunters, toshers, shoremen. These were the London underclasses, at least a hundred thousand strong. So immense were their numbers that had the scavengers broken off and formed their own city, it would have been the fifth-largest in all of England.

The scavengers, in other words, lived in a world of excrement and death.

London Labour and the London Poor

The bone collector’s trade has also declined because most modern cities possess elaborate systems for managing the waste generated by their inhabitants. (In fact, the closest American equivalent to the Victorian scavengers—the aluminum-can collectors you sometimes see hovering outside supermarkets—rely on precisely those waste-management systems for their paycheck.)

We’re naturally inclined to consider these scavengers tragic figures, and to fulminate against a system that allowed so many thousands to eke out a living by foraging through human waste. In many ways, this is the correct response. (It was, to be sure, the response of the great crusaders of the age, among them Dickens and Mayhew.) But such social outrage should be accompanied by a measure of wonder and respect: without any central planner coordinating their actions, without any education at all, this itinerant underclass managed to conjure up an entire system for processing and sorting the waste generated by two million people.

The corpses [of the poor] have no better fate than the carcasses of animals. The pauper burial ground at St Bride’s is a piece of open marshland which has been used since Charles II’s day and there are heaps of bones all over the place. Every Wednesday the remains of dead paupers are thrown in to a hole which is 14 feet deep. A clergyman gabbles through the burial service and then the grave is filled with loose soil. On the following Wednesday the ground is opened again and this goes on until it is completely full. The whole neighborhood is infected from the dreadful stench.

One privately run burial ground in Islington had packed 80,000 corpses into an area designed to hold roughly three thousand. A gravedigger there reported to the Times of London that he had been “up to my knees in human flesh, jumping on the bodies, so as to cram them in the least possible space at the bottom of the graves, in which fresh bodies were afterwards placed.”

But in one crucial sense Dickens and Engels had it wrong. However gruesome the sight of the burial ground was, the corpses themselves were not likely spreading “malignant diseases.” The stench was offensive enough, but it was not “infecting” anyone. A mass grave of decomposing bodies was an affront to both the senses and to personal dignity, but the smell it emitted was not a public-health risk. No one died of stench in Victorian London. But tens of thousands died because the fear of stench blinded them to the true perils of the city, and drove them to implement a series of wrongheaded reforms that only made the crisis worse.

The history of knowledge conventionally focuses on breakthrough ideas and conceptual leaps. But the blind spots on the map, the dark continents of error and prejudice, carry their own mystery as well. How could so many intelligent people be so grievously wrong for such an extended period of time? How could they ignore so much overwhelming evidence that contradicted their most basic theories? These questions, too, deserve their own discipline—the sociology of error.

This social topography would play a pivotal role in the events that unfolded in the late summer of 1854, when a terrible scourge struck Soho but left the surrounding neighborhoods utterly unharmed. That selective attack appeared to confirm every elitist cliché in the book: the plague attacking the debauched and the destitute, while passing over the better sort that lived only blocks away. Of course the plague had devastated the “meaner houses” and “bad streets” anyone who had visited those squalid blocks would have seen it coming. Poverty and depravity and low breeding created an environment where disease prospered, as anyone of good social standing would tell you. That’s why they’d built barricades in the first place.

This is one of the ways that disease, and particularly epidemic disease, plays havoc with traditional histories. Most world-historic events—great military battles, political revolutions—are self-consciously historic to the participants living through them. They act knowing that their decisions will be chronicled and dissected for decades or centuries to come. But epidemics create a kind of history from below: they can be world-changing, but the participants are almost inevitably ordinary folk, following their established routines, not thinking for a second about how their actions will be recorded for posterity. And of course, if they do recognize that they are living through a historical crisis, it’s often too late—because, like it or not, the primary way that ordinary people create this distinct genre of history is by dying.

On its own, a single V. cholerae bacterium is harmless to humans. You need somewhere between 1 million and 100 million organisms, depending on the acidity of your stomach, to contract the disease. Because our minds have a difficult time grasping the scale of life in the microcosmos of bacterial existence, 100 million microbes sounds, intuitively, like a quantity that would be difficult to ingest accidentally. But it takes about 10 million bacteria per milliliter of water for the organism’s presence to be at all detectable to the human eye. (A milliliter is roughly 0.4 percent—four thousandths—of 1 cup.) A glass of water could easily contain 200 million V. cholerae without the slightest hint of cloudiness.

Where sheer physical brutality was concerned, there was little in Victorian society that rivaled the professional medical act of surgery. Lacking any form of anesthesia beyond opium or alcohol—both of which could only be applied in moderation, given their side effects—surgical procedures were functionally indistinguishable from the most grievous forms of torture. Surgeons prided themselves on their speed above all else, since extended procedures were unbearable for both doctor and patient. Procedures that would now take hours to complete were executed in three minutes or less, to minimize the agony. One surgeon boasted that he could “amputate a shoulder in the time it took to take a pinch of snuff.”

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.

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.

This is how great intellectual breakthroughs usually happen in practice. It is rarely the isolated genius having a eureka moment alone in the lab. Nor is it merely a question of building on precedent, of standing on the shoulders of giants, in Newton’s famous phrase. Great breakthroughs are closer to what happens in a flood plain: a dozen separate tributaries converge, and the rising waters lift the genius high enough that he or she can see around the conceptual obstructions of the age.

And here lies an antidote of sorts to the horror of Broad Street, to the grisly image of entire families dying together in their single-room flats: the image of Snow and Whitehead building an unlikely friendship in those late winter months of 1855, drawn together by a terrible outbreak of disease in their neighborhood and, ironically, by Whitehead’s initial skepticism about Snow’s theory. We know very little about the personal interaction between the two men, beyond the crucial data they exchanged, beyond Snow’s sharing of his monograph, and his prophetic statements about the future of cholera. But it is clear from Whitehead’s subsequent recollections that a powerful bond formed between them—the quiet, awkward anesthesiologist and the compulsively social curate—a bond forged both by living through an urban battleground of unimaginable terror, but also by jointly unearthing the secret cause behind the carnage. This is not mere sentimentality. The triumph of twentieth-century metropolitan life is, in a real sense, the triumph of one image over the other: the dark ritual of deadly epidemics replaced by the convivial exchanges of strangers from different backgrounds sharing ideas on the sidewalk. When John Snow first stepped up to the Broad Street pump in early September 1854, it was by no means clear which image would be victorious. London seemed to be destroying itself. You could leave town for a weekend and come back to find ten percent of your neighbors being wheeled down ...

Attention then turned to the East London Water Company. Initially, company representatives swore that all their water had been run through state-of-the-art filter beds at their new covered reservoirs. But reports had surfaced of some customers discovering live eels in their drinking water, which suggested that the filters were not perhaps working optimally.

There are a billion squatters on earth now, and some estimates suggest that their numbers will double in the next twenty years. It’s entirely possible that a quarter of humanity will be squatters by 2030. All the characters of the Victorian underground economy—the mud-larks and toshers and costermongers—may have largely disappeared from cities in the developed world, but everywhere else on the planet their numbers are exploding.

Over 1.1 billion people lack access to safe drinking water; nearly 3 billion—almost half the planet—do not possess basic sanitation services: toilets, sewers. Each year 2 million children die from diseases—including cholera—that result directly from these unsanitary conditions. And so the megacities of the twenty-first century will have to learn all over again the lessons that London muddled through in the nineteenth. They’ll be dealing with 20 million people, instead of 2 million, but the scientific and technological wisdom available to them far exceeds what Farr and Chadwick and Bazalgette had at their disposal.