The Ghost Map Summary

Steven Johnson

The Ghost Map

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The Ghost Map Summary

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The Ghost Map by Steven Johnson is a historical fiction novel that takes place in 1854, amidst a cholera outbreak in Victorian London. Johnson’s story highlights two characters whose investigations lead them to the source of the epidemic. Those two characters are Dr. John Snow and Henry Whitehead, who initially have opposite views on how cholera is spread. Snow believed that it was a waterborne illness, whereas Whitehead, one of his greatest critics, believed the disease was spread through the air. Most scientific minds of the age agreed with Whitehead, believing that the disease came specifically from inhaling the foul smell of the Thames River. This belief that this “miasma” was the culprit touched on more diseases than cholera. Miasma is basically pollution, and the pollution of the Thames was legendary as it was the receptacle for all of London’s waste.

Prior to the cholera outbreak, Dr. Snow’s practice focused mainly on relieving patient pain during surgical procedures and births. He used ether and chloroform to dull the senses and make patients more comfortable. Queen Victoria herself called upon his services to help with the birth of her eighth child. When the cholera outbreak began, Snow dedicated his efforts to finding the cause and patient zero. Whitehead, on the other hand, was not a physician but rather a curate from St. Luke’s in Soho who devoted his time to sitting with the sick and dying to offer them comfort.

In The Ghost Map, Snow and Whitehead discover together the identity of patient zero, and conclude that cholera is indeed a waterborne disease, changing the way the illness was dealt with and prevented.

Patient zero was a five-month-old resident of Soho. The daughter of Thomas and Sarah Lewis had diarrhea—from a then-unknown illness—and the house was overwhelmed with dirty diaper cloths, Thomas and Sarah tossed the used diapers into a wash basin to soak them. That wash water was disposed of in a local cesspool. That particular cesspool fed the Broad Street pump, where many of the local citizens obtained their water. The contamination of that water was the springboard for the cholera outbreak, which was only worsened by the overcrowding and inadequate waste systems. By combining waste water with drinking water, cholera spread like wildfire.

Once contracted, cholera attacks the small intestine. The bacteria causes diarrhea and dehydration so severe that after working harder than usual to maintain circulation, the heart and other organs in the body begin to shut down, leading to death.

This outbreak led to the death of 616 people, most in the Broad Street area. The victims were from a variety of social classes and included artists and socialists—the diseases even touched Karl Marx and his family. This outbreak of cholera had a number of effects on society apart from understanding how the disease is transmitted. It changed the way urban planning was executed as well, as the revelation that the disease was waterborne forced the modernization of urban sanitation, particularly in densely populated areas like Broad Street. Victorian London had become overpopulated because people were living longer and healthier lives. The incorporation of tea into daily diets helped mitigate many waterborne bacteria—yet another reason many scientists and government officials did not readily believe Snow’s assertion that cholera was waterborne. This overpopulation led to the problem of how to handle waste.

The overpopulation also led to an underbelly of people who lived in poverty yet performed crucial roles in the city. People such as the Night-Soil men, who cleared the cesspools of excess excrement, had been largely ignored by the gentry and upper classes despite their importance.

The ghost map itself was Snow’s indication of how the disease spread to infect so many. It included his compiled notes, which helped to prove his theory that cholera was waterborne. Snow’s style of mapping the progression of a disease has become common practice in the field of epidemiology, the study of diseases.  Ghost maps allow these scientists to map and understand disease outbreaks.

The work of Dr. John Snow and Henry Whitehead not only limited what could have been a far deadlier outbreak, but together, they changed the way urbanization and epidemiology was approached. While change did not occur overnight, no longer would London’s solutions to a waterborne illness be comprised solely of trying to clean up the air. Dr. John Snow’s discoveries and innovations, along with his later criticism of those who stubbornly held to the miasma theory, would forever change the way outbreaks and epidemics were analyzed, understood, and ultimately prevented.

Steven Johnson’s book takes place over the course of the week-long epidemic, and is arranged with each chapter representing a day during that deadly week.