Book Review: THE GHOST MAP


The Ghost Map, by Steven Johnson, is very close to a perfect book. The book describes the birth of modern epidemiology as it arose in response to a virulent outbreak of cholera in a particular 1854 London neighborhood. If you, unlike me, are not horribly enthralled by cholera or nerdily swoon at epidemiology, this has the potential to be a very dry read. And, in fact, going into this book I already knew the story of this particular outbreak of cholera because I’d read about it in much less gripping books about Victorian medicine*. What makes The Ghost Map different, and what makes it the kind of book that I now want to thrust into the unsuspecting hands of everyone I know, is that it does a remarkable job contextualizing the outbreak such that you, as a modern reader who likely has no direct experience of cholera, understands the absolute terror the Londoners felt in this outbreak. You feel the visceral urgency that comes with that terror, the awful need to unravel what the horrible riddle that was cholera.

Much of the book follows Dr. Jon Snow**, who is an interesting historical figure in his own right. A pioneer of anesthesiology, Jon Snow also had a fascination with cholera. It was he who, without the aid of developed germ theory, deduced that cholera must be waterborne and traced the outbreak back to a particular water pump on Broad Street. The Ghost Map has shades of narrative non-fiction, just enough to draw Jon Snow and the other players as real people, complete people with thoughts and tragic flaws and beating hearts. The book never tips fully over into narrative non-fiction, restraining itself enough that it does not speak for these historical figures, which I appreciated.

But to say that this is a book about Jon Snow’s prodigious scientific contributions is to give it short shrift. The real strength of the book is that it takes this single narrative thread—Jon Snow’s proto-epidemiological investigations into the 1854 cholera outbreak—and locates it in a myriad of nested lenses. This narrative thread is explored from the lens of the microbial cholera itself, describing cholera’s life cycle and the way cholera adapted to the new context of a dense and dirty human metropolis. This narrative thread is explored from the sociological lens of why Snow’s waterborne theory had to fight so hard to gain traction against the classist and Social Darwinist competing miasmatic theory of cholera transmission. Ultimately, the unifying element of the book is that Stevenson frames the 1854 cholera outbreak in terms of waste recycling—he starts the book with descriptions of the London underclasses who survived by compiling and moving and disposing of the mountains of human waste that Victorian London produced. He frames microbes as creatures whose waste products ultimately gave rise to multicellular creatures like ourselves. It is a fascinating, cyclical framing device that allows the reader to understand just how smoothly all the pieces fit together.

If you are interested in medicine, or the human body, or biological systems, or cityscapes, or Victorian England or just really good non-fiction I cannot recommend this book enough.


*I told you I was into this stuff. I will not apologize for who I am, reader.

**Full disclosure, I read A Song of Ice and Fire before my interest in Victorian cholera outbreaks asserted itself, so every time I read about the illustrious Dr. Jon Snow I have a hard time imagining him as the small, proper Englishman he was. Instead Jon Snow as portrayed by Kit Harrington from the Game of Thrones TV show pops into my head in improbable full costume stalking around Victorian London doing science. Here is an illustration so you, too, can experience this: