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

Henry Whitehead was Snow’s eventual collaborator in proving the waterborne theory of cholera transmission. Although evidently different from Snow—Whitehead was gregarious where Snow was introverted, and a vicar where Snow was a scientist—he had in common with Snow an intellectual open-mindedness and an indifference to received opinions. Like Snow, his way of testing his theories was empirical and local. At the same time that Snow was drawing water from the contaminated Broad Street well to analyze and establishing the drinking patterns of the citizens nearby, Whitehead was interviewing the citizens themselves. 

Whitehead lived to see his and Snow’s theory become accepted, as the miasma theory of cholera transmission became more discredited. He also helped to navigate a second cholera outbreak that occurred in 1886. However, he seems to have understood his role to be secondary to Snow’s, in the discovery of the origins of cholera. He kept a portrait of his late friend in his study, as a reminder of the importance of “‘patient study of the eternal laws’” (227).

Edwin Chadwick was the President of the Board of Health shortly before the 1854 cholera epidemic. (Benjamin Hall had taken over the presidency by the time of the epidemic.) He was an influential figure in ways both good and bad, and his legacy was a mixed one. On the one hand, he was both purposeful and well-intentioned, and as the Board president he helped to usher in a new role for government as tackling urgent health issues and protecting the welfare of the poor. While his conception of government was a modern one, however, his theories around cholera transmission were backwards and misguided. Like many other scientists and government officials at that time, he believed that cholera was caused by inhaling bad smells, such as the stink that arose from sewage and the smell of bodies in pauper graves. Towards this end, he conceived of a scheme to empty the cesspools in front of London houses into the Thames river; therefore, as Johnson states, he “deliver[ed] the cholera bacteria directly to the mouths of Londoners” (120).

Chadwick is responsible for the quote “All smell is disease”(114), a quote which is also the title for Chapter 5 in this book. He is a reminder of the degree to which prejudice and popular theories can sabotage even intelligent and well-meaning people.