Cholera footnote

Even though John Snow had demonstrated that cholera was transmitted by water not air, once the epidemic died down officials replaced the handle of the Broad Street Pump and life returned to normal.

Once the immediate threat had vanished it was easier for leaders and the general population to return to their previous beliefs than it was to accept that those beliefs were mistaken, especially since that would have forced them to make changes in their behaviour.

It wasn’t until 12 years later (1866) that one of Snow’s most outspoken opponents, William Farr, was facing another outbreak in a different part of the city, realised Snow’s theory was correct, and ordered all water to be boiled.

The building of the famous Victorian sewer system under London was begun in 1858, “The Year of the Great Stink”, when Parliament approved the Act to pay the huge expense of building the Victorian sewers.

There are lessons here for any changes we might seek to make:

  1. Changes in beliefs are difficult to accept, especially if they imply changes in behaviour (or expense).
  2. In human society, changes in beliefs and behaviour depend not only on the facts but also on who supports the idea / belief.
  3. The great Victorian sewers that addressed the problem were built by people who still believed that cholera was caused by foul airs and miasma, not by polluted water.

Chapelle, Frank (2005) Wellsprings. New Brunswick, New Jersey: Rutgers University Press. ISBN 0-8135-3614-6. p. 82
Cadbury, Deborah (2003). Seven Wonders of the Industrial World. London and New York: Fourth Estate. pp. 189–192.
Donaldson, L.J. and Donaldson, R.J. (2005) Essential Public Health. Radcliffe Publishing. ISBN 1-900603-87-X. p. 105

Mentioned in wikipedia and here.