Snow, John Dr
ACHIEVEMENT(S): Cholera discovery
DATE/PLACE OF BIRTH: 15 March 1813, at York, England
DATE/PLACE/AGE AT DEATH: 16 June 1858, at London, England. Aged 45
DISCIPLINE: Anaesthetist
FIELD: Medicine
EDUCATION: Private school, York; Hunterian School of Medicine, London;
Westminster Hospital; Royal College of Surgeons
MAJOR WORK: 'On Chloroform and Other Anesthetics', 1858
LIFE AND TIMES: In June 1827, Snow was apprenticed to a licensed surgeon in Newcastle upon Tyne, William Hardcastle, physician to the family of the engineer George Stephenson*.
In 1831, the first cholera epidemic struck England, at the nearby seaport of Sunderland, and Snow was sent by Hardcastle to provide medical assistance at the Killingworth colliery where many cases had been reported. At the age of 23, having served nine years as a medical apprentice, Snow returned to York for a few months.
In the summer of 1836 he toured England and Wales before travelling to London during the following October, in order to begin his formal medical education at the Hunterian School of Medicine in Great Windmill Street. In 1838 was admitted as a member of the Royal College of Surgeons and continued his studies at the University of London Medical School. In 1844 he became an M.D.
Snow meanwhile had set up a practice in one of the poorest areas of London, at Frith Street, Soho. In January 1847 Snow began experimenting with ether and within weeks had invented an apparatus for administering it, which he then demonstrated in the dental out-patients room at St. George's Hospital. The new apparatus was so successful that Snow was immediately invited to work first with Liston*, and quickly became the premier English anesthetist of the day.
In September 1847 he published: 'On Ether', in which he described his apparatus and the properties of the drug, and gave physiological and practical information about its use.
In November 1847, a new anesthetic, chloroform, was introduced by James Young Simpson, and Snow immediately began investigating its effects. The drug became respectable on 7 April 1853, when Snow administered it to Queen Victoria* at the birth of Prince Leopold.
Meanwhile, an outbreak of cholera in London in 1848 gave Snow the opportunity to study the disease, his observations and researches leading him to the realization of its communication by means of a contaminated water supply.
In 1849 he wrote the first of his many papers on the subject, and published his book: 'On the Mode of Communication of Cholera', in which he suggested that water polluted by sewage might be the carrier, and highlighted the dangers of London's cesspools leaking into public wells, and the practice of flushing the contents of the city's water-closets directly into the sewers (rather than into cesspools), and then into the Thames.
Snow's theory and proof of transmission by water infected with fecal matter, while highly influential on such social reformers as John Simon and Chadwick*, also triggered controversy.
During a major outbreak of cholera in London in 1854, Snow carried out brilliant epidemiological investigations to prove his theory. By one detailed survey he was able to show that the areas supplied by water from the Southwark and Vauxhall Water Company (obtained from the contaminated Thames, into which many of London's sewers drained) suffered nine times more fatalities from cholera than the areas supplied by the Lambeth Company, which obtained its water from a source upstream.
His most dramatic achievement came in June 1854, when he pinpointed a Soho water pump as the cause of an epidemic which had, within a radius of a few hundred yards, killed some 500 people in 10 days. Snow discovered that a sewer pipe passed within a few feet of the well, and his belief that contaminated water was the source of infection was entirely vindicated when, having persuaded the unbelieving parish councillors to remove the pump handle, the epidemic ended.
Snow's theory was that cholera was propagated by a living, water-borne, self-reproducing cell or germ, and as precautionary measures he recommended the decontamination of soiled linen, the washing of hands and the boiling of water.
He believed in the intravenous use of saline fluids (now the basis of modern treatment). His writings, particularly his paper "Drainage and Water Supply in Connection with the Public Health" (1858), in which he urged the construction of a new system of sewers, the use of filters by water companies and advised that water be boiled before use during cholera epidemics - were highly influential among the great sanitary reformers of the mid-19th century.
ASSESSMENT: He is best remembered for his seminal paper 'On Cholera', in which he established polluted water as the cause of cholera epidemics.
EXTRA CONNECTIONS: His work related to that of sewer-builder Bazalgette*
His doctor was Richard Bright*
He believed in the miasma* theory of disease
He collaborated with Benjamin Richardson*
ONELINER: John Snow, early epidemiologist
BIBLIOGRAPHY: DNB, DSB
Journal of Medical Biography 3: 160 (1995) & 8: 2 (August 2000)
Halliday, Stephen, The Great Stink of London: Sir Joseph Bazalgette and the Cleansing of the Victorian Capital,Stroud, Glos: Sutton Publishing, 1999
Wikipedia: http://en.wikipedia.org/wiki/John_Snow_(physician)
http://www.amazon.com/The-Ghost-Map-Terrifying-Epidemic/dp/1594482691
http://en.wikipedia.org/wiki/The_Ghost_Map
TEDtalk: https://www.ted.com/talks/steven_johnson_tours_the_ghost_map
LANGUAGE: English
PARENTS: William Snow (d. 1846) and Frances Empsom (1789-1860), married 1812
SIBLINGS: Eight younger siblings - five brothers and three sisters
SPOUSE: None
CHILDREN: None