THE GHOST MAP

An intrepid doctor and an enlightened minister pursue a cholera outbreak to its lair in 1850s London.

It’s in the water, not the air. This was the discovery that young Dr. John Snow presented to skeptical public-health officials, who were committed to the prevailing, centuries-old theory that foul odors carry disease. As Johnson (Everything Bad Is Good for You, 2005, etc.) ably shows, London in 1854 was indeed a stinky city containing much fecal matter from people and animals, as well as waste from manufacturers. It was the waste from a single infected infant, however, that got into the water supply near the popular Broad Street pump in Soho and empowered Vibrio cholerae to kill hundreds. Johnson recounts how Dr. Snow and “affable clergyman” Henry Whitehead walked the streets, first independently and then in concert, to determine who was dying, who was surviving—and where. Snow’s map charting the dimensions of the outbreak, avers Johnson, did not have an immediate effect (other than convincing officials to remove the pump handle, a decision that saved hundreds, maybe thousands), but it has had an enduring one. Science, not superstition, battled a disease, and in the ensuing years, public officials took steps to prevent another outbreak by building the vast sewer system that continues to function in London. In addition to telling the story of the outbreak, Johnson offers mini-lessons on related topics: how cholera kills, how Victorian London dealt with its messes, how and why people cling to false theories. He devotes the final 70 pages to a paean to cities and an assessment of the principal threats to their continuation. He notes that metropolises in developing countries face enormous public-health problems, and he worries about terrorists armed with weaponized viruses and/or nuclear weapons.

Lively and educative.