Universal and Local Scholarship in Public Health
The main article in the Books section in the November 6 issue of The New Yorker is "Sick City" by Steven Shapin. It's an essay on cholera occasioned by Steven Johnson's The Ghost Map: The Story of London's Most Terrifying Epidemic--and How It Changed Science, Cities, and the Modern World.
The article, and the book, focus on the discovery by John Snow, a mid-19th century London physician, that cholera is transmitted by contaminated water. By mapping the incidence of chlolera deaths, Snow traced the locus of terrible London epidemics in 1848 and 1854 to a well in Broad Street, and stopped the spread of the disease by having the handle removed from the pump. Sounds simple now, but it wasn't at a time when cholera was attributed to miasmic air and blamed on the unsanitary habits of poor people, and water-borne bacteria were not recognized as a cause of disease.
This is a fascinating and enormously important story, but I was particularly struck by the following passage near the end of Shapin's article:
The brilliance of Snow's map lay, as Johnson argues, in the way that it layered knowledge of different scales--from a bird's-eye view of the structure of the Soho neighborhood to the aggregated mortality statistics printed in the Weekly Return to the location of neighborhood water supplies--all framed by particular understandings of how people tended to move about in the neighborhood, of the physical proximity of particular cesspools to particular wells, and of the likely behavior of specific, still invisible, and still unnamed pathogens. A city is a concentration of knowledge as much as it is a concentration of people, buildings, thoroughfares, pipes, and bacteria. Maps like Snow's allowed the modern city to remake itself and to understand itself in a new way. They collected different sorts of knowledge, represented them vividly on the scale of a tabletop, and made that representation available as a resource for urban reform: a plan and a plan of action.
I have written before about the relation of the "universal" and "local" aspects of public scholarship. Snow's work is about the best example I can think of.