Plaque: on the John Snow Memorial, North Street Gardens, York YO1 6JF

John Snow was a physician, a pioneer in the fields of anaesthesia and epidemiology, famed for his tracing of the source of a cholera outbreak in Soho and confirming that it is a waterborne disease. He was born on 15 March 1813 in North Street, York, the eldest of the nine children of William Snow (1783-1846), a labourer in the nearby coalyard, and his wife, Frances Askham (1789-1860). In spite of their humble beginnings in what was one of the poorest parts of the city, both parents were keen that their children should better themselves and do well in life. In this, they succeeded; John became a leader in two medical fields; of his brothers and sisters, two became teachers, one a clergyman, one a colliery manager and one ran a temperance hotel in York.

In an age of high infant mortality, William and Frances lost only one child, George, the youngest of the family, who died aged 18 months in June 1830. By 1819 William had changed his job to become a driver of a horse-drawn delivery cab and was able to buy a house in Queen Street and, later, four more houses and a yard in the same street. These were let to tenants to augment the family income. The 1841 census shows that the family had done so well that William was able to move away from the city and was now a farmer in Rawcliffe, north of York. There is no official record of John’s schooling but it is thought that he may well have attended the Dodsworth School in Bishophill in central York which allotted several places to poor children from the congregation of All Saints’ Church in North Street which the Snow family attended.

Apprenticeship in Newcastle

In 1827, when John was 14 years, he was apprenticed for six years to William Hardcastle, a surgeon-apothecary at Long Benton, a suburb of Newcastle upon Tyne. Hardcastle was born in York in 1794 and baptised at St John’s Church, Ousebridge which stood on the corner of North Street so he probably knew the Snows well. He had served his apprenticeship in York before going to Newcastle in 1815. John’s maternal uncle, Charles Empson, was a Newcastle bookseller and a friend of Hardcastle so no doubt John’s parents thought that their eldest child would be in safe hands in the North-East.

In 1831 Hardcastle was appointed to attend the poor in the Newcastle area during the cholera epidemic of 1831-2 and sent John to treat the miners at Killingworth colliery. It was his first encounter with the disease that was later to occupy so much of his time. After attending classes at the Newcastle School of Medicine in 1832-3 and completing his apprenticeship, he became an assistant, aged 20, first to a Mr Watson, general practitioner in Burnopfield, about eight miles south-west of Newcastle, and then to Joseph Warburton in Pateley Bridge, a small town some 30 miles west of York.

At the age of 17 whilst still in Newcastle, John had become interested in both the temperance movement and vegetarianism, to both of which he rigidly adhered for more than eight years. He helped to found York Temperance Society in June 1836 on a visit to his native city. However when his health began to deteriorate in the mid-1840s, both he and his friends thought this might be due to his rigid diet so he returned to eating meat and drinking an occasional glass of wine.

Medical training

By October 1836 when he was 23, John had scraped together enough money to enrol at the Great Windmill Street School of Medicine in London. After six months’ surgical practice at Westminster Hospital his training was complete. He became a member of the Royal College of Surgeons in May 1838 and a licentiate of the Society of Apothecaries in the following October.

In September 1838, then aged 25, John moved to 54 Frith Street, Soho, setting up in general practice while also working in the out-patient department of Charing Cross Hospital and as a medical officer for several sick clubs. It was impossible for poorer families to afford doctors’ bills in those days so many workers paid a small amount each week into a friendly society sick club. The society would invite tenders from local doctors willing to take on their members for treatment and medicines. This work was poorly paid but gave John valuable experience. He gained further medical qualifications from London University, receiving his MB in 1843 and MD in 1844. In 1845 he was, for a short time, a lecturer in forensic medicine at the Aldersgate School of Medicine. John was kept busy with sick-club and dispensary work but his private practice did not become well established until the late 1840s and the introduction of anaesthesia. He became a member of the Royal College of Physicians in 1850 when he was 37.

John believed that he owed his successful practice in London and his medical achievements to his early connection with the Westminster Medical Society which merged with the Medical Society of London in 1851. Having joined the society in 1837, becoming a committee member in 1844 and its president in 1855, John became a vigorous debater at society meetings and contributed regularly to medical journals. He was also a member of the Medico-Chirurgical Society and one of the first members of the Epidemiological Society which was founded in 1850. He devised several new medical instruments including, in 1841, a pump that could be used for artificial respiration and, in 1844, one to remove fluid from the chest while avoiding the entry of air, so preventing the collapse of the lung.


A dentist based in Gower Street, London, James Robinson (1813-62), was the first in Britain to use ether as an anaesthetic when he extracted a tooth on 19 December 1846. Very soon afterwards John began his research into ether administration and realised that an efficient inhaler to control vapour strength was fundamental to the safe administration of any anaesthetic. He went on to develop several instruments to facilitate the use of anaesthetics. By the beginning of February 1847 he had already administered ether at St George’s Hospital, London for eight surgical operations and he now began a successful career as an anaesthetist, quickly developing a specialist practice working in many London hospitals and with some of the most eminent surgeons.

James Young Simpson (1811-70), a Scottish obstetrician, used to meet in the evening with two friends at his home, 52 Queen Street, Edinburgh, to experiment with chemicals to see if they had any anaesthetic properties. On 4 November 1847, they all inhaled chloroform. After an initial positive feeling, they all passed out only regaining consciousness the following morning. Following experiments on animals and inhaling it himself, John Snow adopted the use of chloroform without hesitation, though he always held that ether was the safer agent. John’s reputation for safety and skill led to his successful administration of chloroform to Queen Victoria during the births of Prince Leopold (1853) and Princess Beatrice (1857).

Research into causes of cholera

His reputation as an anaesthetist is probably overshadowed in modern times by the acknowledgement of John’s pioneering work in the field of public health and hygiene, in particular his discovery that cholera is a waterborne infection. Following an outbreak in 1849, he published a paper, On the Mode of Communication of Cholera, outlining his theory but it received little attention from the medical world. Doctors believed that cholera was transmitted through the air but John felt that, if this were true, symptoms would first appear in the lungs rather than the stomach and bowel.

There was a further outbreak of cholera in Broad Street, London in 1854 when more than 500 people died within the space of 10 days. John obtained a list of the deaths recorded by the General Register Office and compiled a map of their location. This indicated that most had occurred within the area of the Broad Street pump and the local board of guardians agreed that the pump handle should be removed. Although this has been described as the dramatic end to the outbreak, in fact the epidemic was already receding but a parish cholera enquiry committee was set up and the source of the outbreak officially identified.

Contaminated water supply

The unveiling of Dr. John Snow’s memorial by his descendants, Dr Geoff Snow and Dr Stephanie Snow
The water pump memorial with the handle removed

John first became interested in water supplies to south London following the 1849 epidemic when he noted that cholera fatality rates were particularly high in the areas supplied by two water companies: the Lambeth Waterworks Company and the Southwark and Vauxhall Waterworks Company. In 1852 the Lambeth company moved its waterworks further up river away from the contamination caused by the city’s sewage. John undertook an investigation to calculate the number of deaths from cholera per 10,000 houses during the first seven weeks of the 1854 epidemic. The conclusion of this investigation was that the mortality rate for the houses supplied by the Southwark and Vauxhall was between eight and nine times greater than houses supplied by the Lambeth which had the cleaner water supply. John contended that his investigations completely substantiated his theory but, again, the medical world would not accept that infected water was a primary source of the disease. It was only in the 20th century that the accuracy of John’s theory, and the quality of his epidemiological investigations, became widely appreciated.

Early death

On 10 June 1858, while completing a paper On Chloroform and other Anaesthetics, John suffered a stroke. His condition deteriorated and he died, unmarried, on 16 June aged 45. His clergyman brother, William, was with him when he died at home, 18 Sackville Street, Piccadilly, London where he had lived since 1852. Post-mortem examination showed evidence of old pulmonary tuberculosis and advanced renal disease. He was buried in Brompton cemetery on 21 June 1858. Friends and colleagues erected a monument over his grave which was destroyed by enemy action in April 1940. A replica was erected in 1951 by the Association of Anaesthetists of Great Britain and Ireland.

Today John Snow is relatively unknown but, in his field, he is an acknowledged pioneer and his achievements are celebrated. In 2001 John Snow College was founded at Durham University’s Queen’s Campus in Stockton-on-Tees and, in 2003, a poll of British doctors ranked John Snow as the greatest physician of all time.



Stephanie J. Snow, ‘Snow, John (1813-1858)’, Oxford Dictionary of National Biography, (Oxford, 2004; online edn, May 2008 –, accessed 27 June 2016]

Spence Galbraith, Dr John Snow (1813-1858): His Early Years, An account of the family of Dr John Snow and his early life (London, 2002)

Sheena Hastings, ‘Unsung in his own land, John Snow is a hero who saved countless lives’ (Yorkshire Post, 18 February 2013)

University of California, Los Angeles, Dept of Epdemiology


© Dinah Tyszka


John Snow Memorial (watercolour by Allan T Adams)