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Book review, “The Ghost Map,” on the London Cholera Epidemic of 1854

Friday, 6th of January 2017

Book review, “The Ghost Map,” on the London Cholera Epidemic of 1854

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A Drink of Death

By DAVID QUAMMEN

New York Times Book Review

Several days ago I picked up a serious magazine and found Steven Johnson, among a panel of experts, discussing literacy in the age of video games. He offered some mischievously counterintuitive thoughts, similar to those in his 2005 book about popular culture, “Everything Bad Is Good for You.” One of his views, much simplified, is that Grand Theft Auto makes children smart. And maybe it does: some players evidently compose their own guidebooks for that vivid, ugly game, offering hundreds of pages of tactical tips and strategic advice. “If you spend time assessing these complex systems and writing about them,” Johnson told his fellow panelists, “then you should be able to take that skill and apply it to a real-world ecosystem or a political system or a cultural system.”

Johnson himself, having spent much of his childhood playing baseball-simulation games rich with complexity and data, has now applied his own nimble cognitive skills to a real-world ecosystem much messier than any imaginary ball diamond or video-game universe: the city of London in the mid-19th century, with its 2.4 million humans, nightmarish plumbing and burden of dangerous microbes.

“The Ghost Map” takes Johnson, who has also written books on neuroscience and on the cultural implications of computer interfaces, in some new directions — into historical narrative and the ecology of infectious disease. This time he acknowledges that not everything bad for you is good. In fact some of it, like the bacterium Vibrio cholerae, can be deadly.

There´s a great story here, one of the signal episodes in the history of medical science, and Johnson recounts it well. It centers, figuratively and literally, on the infamous Broad Street pump. That pump, which was public, free and previously considered a safe source of drinking water, drew from a well beneath Golden Square, home to some of London´s poorest and most overcrowded people. In the last week of August 1854, many residents of Golden Square suddenly took sick and began dying. Their symptoms included upset stomach, vomiting, gut cramps, diarrhea and racking thirst. Whatever the cause, it was fast — fast to kill (sometimes within 12 hours of onset) and fast in spreading to new victims. “Hundreds of residents had been seized by the disease within a few hours of one another, in many cases entire families, left to tend for themselves in dark, suffocating rooms,” Johnson writes. Seventy fatalities occurred in a 24-hour period, most within five square blocks, and hundreds more people were in danger. “You could see the dead being wheeled down the street by the cartload.”

The medical authorities quickly enough put a name to this affliction. It was cholera, known and dreaded in Britain since earlier outbreaks in the 1830s and ´40s, one of which had killed 7,466 Londoners within two years. But naming the disease was far easier than curing it in an individual, or stopping its spread in a population. None of the authorities understood what cholera was or how it worked. Conventional wisdom took it for a miasmal disease, traveling by air as some sort of lethal vapor — a killer smell. If it preferentially affected the poor, by this line of thought maybe that was because they lived in fetid circumstances.

John Snow, a private physician who had treated cholera during his apprenticeship in Newcastle, had a different idea. He believed that the disease was caused by an unidentified agent that victims ingested, probably in contaminated drinking water. “Cholera wasn´t something you inhaled,” Johnson explains, describing Snow´s crucial insight. “It was something you swallowed.”

John Snow was a “consilient” thinker, according to Johnson, using an old word recently revived by E. O. Wilson, meaning that Snow combined insights from different disciplines and different scales of investigation. He examined water samples under a microscope. He studied the weekly statistics on cholera death throughout London, looking for geographical patterns. Eventually he drew a map — the “ghost map” of the title — that showed the correlation between cholera cases and walking distance to the Broad Street pump. One week after the outbreak began, having heard Snow´s arguments, the local Board of Governors ordered the shutdown of the Broad Street pump. Soon afterward the epidemic sputtered to an end. And that´s the satisfying denouement of the tale in its often-told, bare-bones form: John Snow pioneers the science of epidemiology and, by having a pump handle removed, saves hundreds of lives. Among the points usually omitted, however, is that Snow himself never managed to see or identify what it was, in the water, making people sick. He got the epidemiology, but not the bacteriology.

The fuller version of the story, as told by Johnson, is more complicated. It includes another key character, an assistant curate named Henry Whitehead, who ministered to residents of Golden Square and knew the details of their lives well enough to identify the epidemic´s starting point (a sick baby, whose diapers contaminated the Broad Street well). It also includes an Italian researcher named Filippo Pacini, who identified the cholera bacterium around the same time John Snow failed to see it, and who published a paper that lay ignored for 30 years.

Most intriguingly, Johnson goes beyond the immediate details of the 1854 epidemic to consider such related matters as the history of toilets, the upgrading of London´s sewer system, the importance of population density for a disease that travels in human excrement, and the positive as well as negative aspects of urbanization itself. Never before Victorian London, Johnson reminds us, had 2.4 million primates of any species lived together within a 30-mile perimeter.

By solving the cholera mystery, Johnson asserts, John Snow and Henry Whitehead helped make the world safe for big cities. And cities are “where the action is” (he really does use that phrase, alas), being “centers of opportunity, tolerance, wealth creation, social networking, health, population control and creativity.” So it seems once again that, in the long run, everything bad is good for you — even crowded cities, even cholera, unless you happen to be one of the dead people on the cart.

Steven Johnson is of course a consilient thinker himself, and a smart one, no doubt made even smarter by all that simulated baseball. His book is a formidable gathering of small facts and big ideas, and the narrative portions are particularly strong, informed by real empathy for both his named and his nameless characters, flawed only sporadically by portentousness and small stylistic lapses. One tic, which seems to me not just a matter of careless wording, is his overly frequent use of the word “ironically” and its variants: “The tragic irony of cholera” was one thing, “the dominant irony of the state of British public health” was something else, the “dark irony” of the miasma theory was this, the “sad irony” of Snow´s argument was that — and I could cite many other instances. That´s a little too much irony for one short book, and it seems to reflect Johnson´s insistence that his insights, beyond being interesting and significant, are ingenious reversals of expectation.

Sometimes they are. It´s fascinating to read that because of the life history of Vibrio cholerae, which circulates in water flowing from one human gut to another, the bacterium never caused big trouble in Britain until crowded urban conditions exposed people to drinking one another´s sewage. But Johnson´s account of the 1854 epidemic, along with the meditation on cities that he extrapolates from it, doesn´t need to call attention to its own cleverness. “The Ghost Map” is elegantly sufficient, without that, to get readers to do some thinking on their own.

David Quammen´s most recent book is “The Reluctant Mr. Darwin.”