The State Doctor, 1840-1850.

UNITED KINGDOM - SEPTEMBER 13: Colour lithograph associated with a cholera epidemic. The �State� is being compared to a �Doctor� who has a variety of remedies for the country�s ills many of which are either ineffective, such as �Cordials for the Cholera�, or harmful: �Church patronage�. (A bolus is a large pill or intravenous dose of a drug.) John Snow's (1813-1858) work was vital in establishing the water-borne nature of cholera which first appeared in Britain in 1831. Epidemics were exacerbated by rapid urbanisation and associated poor public hygiene. Cholera hit both rich and poor, and public pressure led to legislation which made dramatic improvements in all aspects of public health provision. (Photo by SSPL/Getty Images)