Snow , John , 1813-1858 , anesthetist and epidemiologist

John Snow was born on 15 March 1813 in York, the eldest son of William Snow, farmer. He was educated locally at a private school, until the age of fourteen when he was apprenticed to William Hardcastle, a surgeon in Newcastle-upon-Tyne. In Newcastle he worked as one of three surgeon apothecaries at the Lying-In Hospital, where he was also secretary. He also held an appointment as mining doctor at the Killingworth Colliery. This work brought him into contact with George and Robert Stephenson, who in 1827 were listed as patients of his practice. Throughout the Cholera epidemic of 1831-32 he attended victims at the colliery. During his apprenticeship, 1827-1833, he became a vegetarian and teetotaler.

Between 1833 and 1836 he was an assistant in practice, first in Burnopfield, Durham, and then in Pateley Bridge, North Yorkshire. During this time he often returned to York and was much involved in the temperance movement. In 1836 Snow decided to further his medical education in London. He undertook the journey on foot, walking via Liverpool, Wales and Bath. In October 1836 he became a student at the Hunterian School of Medicine, Great Windmill Street, where his initial research in medicine began, the subject being the toxicity of arsenic. In October 1837 he began to attend the medical practice at the Westminster Hospital. He was admitted a member of the Royal College of Surgeons of England on 2 May 1838, and in October of that year he became a licentiate of the Society of Apothecaries.

Snow set up practice in his new home at 54 Frith Street from 1838. To further his medical knowledge Snow regularly attended the meetings of the Westminster Medical Society (later the Medical Society of London), having joined as a student member in 1837. He presented the results of his research on a number of diverse scientific problems at the Society's meetings, and subsequently published articles on them in the medical journals, throughout the late 1830s and early 1840s. The two dominant themes were toxicology and respiratory physiology. His first published paper, Arsenic as a Preservative of Dead Bodies', appeared in The Lancet in 1838. However, his most well known paper was published in 1842, On Asphyxia, and on the Resuscitation of Still-born Children. Other topics included the danger of candles incorporating arsenic, postscarlatinal anasarca, and haemorrhagic smallpox. By the end of this phase of his career,the name of John Snow was quite well known to anyone who read the English Medical Press' (Shephard, 1995, p.44).

He graduated MD from London University on 20 December 1844, having graduated MB in November 1843. At this time, after the immense pressure of hard work, he had a breakdown and it is thought suffered an attack of tuberculosis (Fraser, 1968, p.504). His health was further affected during the following year when he suffered from renal disease. It was in 1845 that he was appointed lecturer on forensic medicine at the Aldergate Street School of Medicine, a position he held until 1849 when the school closed.

In 1846 Snow became interested in the properties of ether, which had been newly adopted in America as an anaesthetizing agent. His work in anesthesia had begun during his earlier investigation into asphyxia of the newborn. Snow made great improvements in the method of administering the drug, and obtained permission to demonstrate his results in the dental out-patient room at St George's Hospital. This proved so successful that he won the confidence of Robert Liston, the eminent surgeon, and so the ether practice of London came entirely into his hands. Despite having practically introduced the scientific use of ether into English surgery, he had `so well balanced a mind that he appreciated the value of other anaesthetizing agents, more particularly chloroform' (DNB, 1898, p.208). It was this drug that he famously administered to Queen Victoria during the birth of Prince Leopold, 7 April 1853, and again, a few years later, during the birth of Princess Beatrice, 14 April 1857.

Snow is famous for his scientific insight which led to the theory that cholera is communicated by means of a contaminated water supply. His essay On the Mode of Communication of Cholera, was first published in 1849. The second edition, in 1855, included a more elaborate investigation into the effect of the water supply on certain districts of South London during the 1854 epidemic. Ultimately then Snow became

`widely recognised as one of the founding fathers of epidemiology as well as a leading figure in the initial development of anaesthetics in Britain' (Galbraith, 2002, p.1).

During the intervening years between the two editions of his publications on cholera, Snow was admitted as a licentiate of the Royal College of Physicians and was a founder member of council of the Epidemiological Society of London, in 1850. In 1852 the Medical Society of London selected him orator for the following year. It was also in 1853 that he moved home and practice to 18 Sackville Street. He was a member of the Royal Medical Chirurgical Society and the Pathological Society, and was President, in 1854 of the Physiological Society, the Medical Society of London in 1855, and in 1857 of the Epidemiological Society.

Snow died unmarried, at the age of 45, on 16 June 1858. The direct cause of death was a stroke, however the autopsy revealed his health for many years had been undermined by the earlier attacks of tuberculosis. He was engaged on his work, Chloroform and Other Anaesthetics, at the time of his death. This was edited and published posthumously by his friend and fellow physician Sir Benjamin Ward Richardson. Snow was buried at Brompton Cemetery, where his colleagues and friends erected a monument in his memory.

Publications:
`On Distortions of the Chest and Spine in Children from Enlargement of the Abdomen', London Medical Gazette, 1841, 28, pp.112-116
On the Inhalation of the Vapour of Ether in Surgical Operations (London, 1847)
A Letter to the Right Honorable Lord Campbell, Lord Chief Justice of the Court of Queen's Bench, on the Clause Respecting Chloroform in the Proposed Prevention of Offences Bill (London, 1851)
On the Mode of Communication of Cholera (London, 1849, 2nd ed. 1855) - translated into German, Quedlinburg, 1856
On Chloroform and Other Anaesthetics, John Snow, edited with a memoir, Benjamin Ward Richardson (London, 1858)
On Narcotism by the Inhalation of Vapours, John Snow, with an introductory essay by Richard H. Ellis (London, 1991)
Death from Amylene (date & place of publication unknown)

Publications by others about Snow:
Memoir by B.W. Richardson in On Chloroform and Other Anaesthetics, John Snow, edited by Benjamin Ward Richardson (London, 1858)
Dr John Snow (1813-1858): His Early Years: An Account of the Family of Dr John Snow and his Early Life, Dr Nicol Spence Galbraith (London, 2002)