Source: BMJ 332, 1220, May 20, 2006.
The Medical Detective:
John Snow and the Mystery of Cholera
Granta Books, London. 2006, ISBN-13: 978-1-86207-842-0
Also issued in the United States
The Strange Case of the
Broad Street Pump: John Snow and the Mystery of Cholera.
University of California Press, January 15, 2007, ISBN: 0520250494
John Snow is
perhaps the only doctor ever to be considered the founder of two medical
disciplines: epidemiology and anaesthesiology. An early believer in the theory
of contagion, he grasped the opportunity of a peculiarity in the water supply in
London to gather quantitative evidence supporting his theory that cholera was
transmitted by polluted water.
In 1853-4, when a
cholera pandemic hit London, one of the two major water supply firms, the
Lambeth Company, had moved its Thames intakes upriver, above the tidal (and
therefore sewage) reach. Snow showed that most of the cholera deaths occurred
among clients of the other major water provider, the Southwark and Vauxhall
Company, which still pumped its water in a polluted area of the Thames in the
heart of London. We know a great deal about Snow's large scientific heritage
because he was a prolific writer. But very little written testimony exists about
his personal life and psychology beyond an expanded obituary.
Given the limited
biographical material available, it seems that everything that might be written
about Snow has already been said by other authors, or collected by Frerichs on a
website devoted to Snow (www.ph.ucla.edu/epi/snow.html). Indeed, Snow's fans
will not learn anything new about him in The Medical Detective. Still,
Sandra Hempel has succeeded in drawing a three-dimensional portrait of Snow by
abundantly describing the place, time, and society in which he lived.
Detective reads like a well informed
novel featuring Chadwick and Dickens, Queen Victoria and Florence Nightingale,
and digressions on the history of Victorian medicine, of ether and chloroform,
and of cholera. A mythical image of Snow as a brilliant doctor with a
penetrating intuition about the cause of cholera and who ingeniously found a way
to test it emerges. However, in contributing to Snow's mythology, Hempel fails
to address some basic questions any detective would ask. Why Snow? Why London?
After all, many bright physicians in Europe and elsewhere were tracking the
causes of cholera at the same time. Many shared his contagionist views. But Snow
lived in an appropriate socio-political and scientific environment. He had the
opportunity to team up with William Farr, medical registrar for England and
Wales, whose offices collected death certificates and reported their aggregated
A key figure of
Victorian medicine, Farr played a crucial role in Snow's success, which is not
appreciated as much as it should be by Hempel. In December 1853, the registrar
general had first noticed that the districts partially supplied with the
improved water from the Lambeth Company suffered much less than the other
districts from cholera, although, previously, these same districts suffered
about as much as those supplied entirely by the Southwark and Vauxhall Company.
Farr provided Snow with the names and addresses of the dead and made Snow's
demonstration possible. Farr did not share Snow's views on the role of polluted
water, but he was instrumental in the success of Snow's endeavour.
Snow is already
the hero of an excellent children's book (The Blue Death: The True Story of a
Terrifying Epidemic. London: Hodder Children's Books, 2001). Hempel has now
staged him as a brilliant detective and paved the road for a popular movie,
which will finally let Snow enter the pantheon of great doctors.
Alfredo Morabia, professor of epidemiology
City University of New York, United States email@example.com
click to return to the Books on Snow site