The Ghost Map: The Story Of London's Most Terrifying Epidemic - and How It Changed Science, Cities and the Modern World, Johnson - B

                                 In 1854, London had two-and-a-half million people crammed inside a 30 mile circumference and no system for the removal of waste. That job was left to scavengers who scoured the city for anything of value and night-soil men who emptied the city's cesspools. The city had grown in fifty-years from a million, totally lacked the infrastructure to handle that growth and was literally drowning in its own filth. In September, cholera broke out in the Golden Square neighborhood of Soho and it broke out with a vengeance. A disease that usually took days to kill was now felling entire families in 24 hours or less. 

                                  A well on Broad Street was examined and a sample of its water taken by Dr. John Snow. But the technology of the times was not able to analyze and assess the sample. Snow was the first medical professional to propose that cholera was a waterborne disease. He did so in the face of an establishment that believed in the miasma theory that all illnesses are airborne. So, he decided to track deaths, their location and their source of drinking water.  A week into the crisis, he convinced the supervisors to shut down the Broad Street well. It was the first scientifically driven preventive measure ever taken against the disease. 

                                   Snow put together a map that convinced the local clergyman of the waterborne theory, and it was adopted by the Vestry Committee. Slowly and over time, the theory gained traction. Recognition of the pollution of the Thames as a source of waterborne disease and endless stench led to the construction of a sewer system, moving storm water and waste far to the east and hopefully out to sea. The sewers built in the mid-19th century are the backbone of today's system in London. "Establishing sanitary water supplies and waste management systems became  the central infrastructure project of every city on the planet." Electrification came later, but without a sewer system, the world's cities could not continue to grow and prosper.

                                     This book is much more than a history of a singular event. Rather, it is a far ranging and enchanting story of English history, sociology, and politics along with updates on 19th century medicine and public health. Thanks to my brother Bill for the recommendation.