“
Snow was a storyteller as well as a scientist, so he deployed anecdotes to put faces to his number in the hope of persuading his medical colleagues of cholera’s waterborne spread. There was a woman, “the widow of a percussion-cap maker,” who had moved from Soho to the West End some months earlier but had not lost her taste for Broad Street’s water. She had arranged for bottles of it to be brought to her by cart. There was a delivery on August 31. She drank from it then and the next day, and she shared it with a niece who lived in Islington, another district still untouched by cholera. Both died. Seven workmen making dentists’ materials at numbers 8 and 9 Broad Street were “in the habit of drinking water from the pump, generally drinking about half-a-pint once or twice a day.” Cholera killed them all—but two people who lived in the same building who did not draw their water from the pump experienced only bouts of diarrhea. Both lived. A factory at 37 Broad Street provided its workers with barrels of pump water and lost eighteen out of a staff of two hundred. A brewery down the road gave its seventy men malt liquor; no one drank water; none fell ill. Tellingly, the Broad Street outbreak did not single out the abject poor. Rather, Snow wrote, “the mortality appears to have fallen pretty equally amongst all classes, in proportion to their numbers.” He concluded that “out of rather more than six hundred deaths, there were about one hundred in the families of tradesmen and other resident house holders.” The most wretched people in the parish, those locked in the workhouse, were almost entirely spared. That building was bordered on three sides by streets in which the outbreak raged, but lost only 5 of its 535 inmates; if it had seen the same mortality as those richer households, Snow wrote, “upwards of one hundred persons would have died.” What had saved them? The workhouse had its own pump, “and the inmates never sent to Broad Street for water.” This was a refutation of the argument that disease explicitly targeted the poor, either as punishment for their ineradicable sins or because their poverty exposed them to miasmas those above them avoided. Snow kept going, seeking out the details of death after death, and those of seemingly anomalous survivals. He finished his review of the first week’s deaths in just four days, delivering his results to parish authorities on Thursday, September 7. The next morning the parish took perhaps the most famous single action in the history of public health: it ordered that the handle from the Broad Street pump be removed. If Snow was right, the poison that had ruined the district would be cut off at its source, and the epidemic would end. It did.
”
”
Thomas Levenson (So Very Small: How Humans Discovered the Microcosmos, Defeated Germs--and May Still Lose the War Against Infectious Disease)