In 1849 Snow published a small pamphlet “On the Mode of Communication of Cholera” where he proposed that the “Cholera Poison” reproduced in the human body and was spread through the contamination of food or water. This theory was opposed to the more commonly accepted idea that Cholera, like all diseases, was transmitted through inhalation of contaminated vapors. Although he was awarded for this work, without the technology and knowledge that we have today, Snow had no way to prove his theory.
It wasn’t until 1854 that Cholera struck England once again, that Snow was able to legitimate his argument that Cholera was spread through contaminated food or water. Snow, in investigating the epidemic, began plotting the location of deaths related to Cholera (see illustration). At the time, London was supplied its water by two water companies. One of these companies pulled its water out of the Thames River upstream of the main city while the second pulled its water from the river downstream from the city. A higher concentration of Cholera was found in the region of town supplied by the water company that drew its water form the downstream location. Water from this source could have been contaminated by the city’s sewage. Furthermore, he found that in one particular location near the intersection of Cambridge and Broad Street, up to 500 deaths from Cholera occurred within 10 days.
After the panic-stricken officials followed Snow’s advice to remove the handle of the Broad Street Pump that supplied the water to this neighborhood, the epidemic was contained. Through mapping the locations of deaths related to Cholera, Snow was able to pinpoint one of the major sources of causation of the disease and support his argument relating to the spread of Cholera.
The ghost map : the story of London’s most terrifying epidemic and how it changed science, cities, and the modern world New York : Riverhead Books, 2006 Steven Johnson Cholera England London History 19th century Hardcover. 299 p. : ill., maps ; 24 cm. Includes bibliographical references (p. -290) and index. Clean, tight and strong binding with clean dust jacket. No highlighting, underlining or marginalia in text. VG/VG
The Ghost Map takes place in the summer of 1854. A devastating cholera outbreak seizes London just as it is emerging as a modern city: more than 2 million people packed into a ten-mile circumference, a hub of travel and commerce, teeming with people from all over the world, continually pushing the limits of infrastructure that’s outdated as soon as it’s updated. Dr. John Snow – whose ideas about contagion had been dismissed by the scientific community – is spurred to intense action when the people in his neighborhood begin dying. With enthralling suspense, Johnson chronicles Snow’s day-by-day efforts, as he risks his own life to prove how the epidemic is being spread.
When he creates the map that traces the pattern of outbreak back to its source, Dr. Snow didn’t just solve the most pressing medical riddle of his time. He ultimately established a precedent for the way modern city -dwellers, city planners, physicians, and public officials think about the spread of disease and the development of the modern urban environment. The Ghost Map is an endlessly compelling and utterly gripping account of that London summer of 1854, from the microbial level to the macrourban theory level and the human level.