We visited #RijksmuseumBoerhaave in #Leiden today and I met a relative of #JohnSnow’s #CholeraMap

In 1866 #Utrecht was faced with a #cholera epidemic. In less than a month no fewer than 61 residents of the Gasthuissteeg fell prey to the disease, 38 of whom died.

The map shows deaths, cholera illness and other illness, and pumps. #DataViz #epidemiology #HistSci