The Other John Snow

History is one of my favorite subjects and I always enjoy finding out more about the past. Steven Johnson’s The Ghost Map: The Story of London's Most Terrifying Epidemic - and How It Changed Science, Cities, and the Modern World details the 1854 Broad Street cholera outbreak in London, the scientist who investigated it, and the resistance he encountered. 

At the time of the 1854 outbreak, John Snow was already an accomplished doctor, highly regarded for his skill and advancements with anesthesia. Snow witnessed some of the earliest uses of ether on patients about to undergo surgical procedures.  However, its results were mixed—some patients would remain unconscious throughout the surgery while others would regain consciousness in the middle of an operation. Snow thought that the problem was an issue of dosage. He knew that the concentration of gas varied with temperature. The colder the operating room, the lower the dosage the patient received. Snow performed a series of experiments, and within months of first seeing ether used in surgery, he published his “Table for Calculating the Strength of Ether Vapor.” Regarded as the best anesthesiologist in London, Snow was even called upon to administer anesthesia to Queen Victoria during one of her procedures. 

Cholera outbreaks had been erupting around the world, having killed hundreds of thousands by the time of the 1854 outbreak in London. Medical thinking was divided between two camps, those who believed it was contagious and those who believed in the theory of miasma. It was thought that cholera was either spread person to person, or it was more widely believed that cholera existed in a noxious air in unsanitary areas.  Snow had investigated previous outbreaks and had realized that the outbreaks centered around shared water supplies. He theorized that cholera wasn’t spread through direct person to person contact, or through the air, but that it was waterborne. He published a paper reporting his findings that was met with a tepid reception—the English medical community remained skeptical. 

The bulk of the book follows the day-to-day activities of Reverend Henry Whitehead as he visited the sick, going door to door on Broad Street. Combined with his own thorough investigation of those fallen ill with cholera, John Snow was able to narrow down and prove that the source of the cholera outbreak could be linked directly to the water pump at the end of Broad Street. It wasn’t until years after his death that Snow’s work was finally accepted by London health officials, who finally began to issue warnings to boil water during cholera outbreaks. 

Derek Smith

Derek is currently enrolled in Algonquin College’s Professional Writing program, is an avid hat-wearer and a voracious reader.