Ignorance is a Killer

Success is meant to smell sweet, but 150 years ago, as London ballooned to accommodate 2.5 million souls, becoming the largest city the world had ever seen, it quite frankly stank.

In this hub of a glorious, steam-driven empire, the average life expectancy of the city's poorest was only 16, and the cellars of even the better off were often full of excrement. Still, the muck signaled a business opportunity to the 100,000 or so toshers (copper salvagers), mudlarks and bone-pickers who crammed the city's margins, scavenging its corpses or sifting through its effluvia on the banks of the Thames. The air in parts of the capital was so appalling that when, in 1854, cholera struck on Broad Street in the Soho district and quickly developed into the worst epidemic in the city's history, it was hard to doubt the official line — let alone the evidence of the senses — that the stink was to blame.

In The Ghost Map, Steven Johnson gives a ground-zero account of the outbreak that would take 50,000 lives before it was done. "Imagine the terror and panic," he writes, "if a biological attack killed 4,000 otherwise healthy New Yorkers over a 20-day period. Living amid cholera in 1854 was like living in a world where urban tragedies on that scale happened week after week."

At the center of his tale is John Snow, the doctor who overcame the medical establishment's entrenched belief that cholera lurked in the city's "miasma," its bad air, and proved the true cause by painstakingly charting the contagion against London's water supply. The resulting map provided a founding case study for epidemiology. But as readers of previous books by Johnson might expect — among them Mind Wide Open and last year's defense of popular culture, Everything Bad Is Good For You — the author has also chosen his subject for the light it can shine into other corners.