John Snow (15 March 1813 – 16 June 1858) was an English physician and a leader in the development of
anaesthesia
Anesthesia is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), am ...
and
medical hygiene. He is considered one of the founders of modern
epidemiology
Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population.
It is a cornerstone of public health, and shapes policy decisions and evide ...
, in part because of his work in tracing the source of a
cholera outbreak in Soho, London, in 1854, which he curtailed by removing the handle of a water pump. Snow's findings inspired the adoption of anaesthesia as well as fundamental changes in the water and
waste systems of London, which led to similar changes in other cities, and a significant improvement in general
public health
Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals". Analyzing the det ...
around the world.
Early life and education
Snow was born on 15 March 1813 in
York
York is a cathedral city with Roman Britain, Roman origins, sited at the confluence of the rivers River Ouse, Yorkshire, Ouse and River Foss, Foss in North Yorkshire, England. It is the historic county town of Yorkshire. The city has many hist ...
, England, the first of nine children born to William and Frances Snow in their
North Street home, and was baptised at
All Saints' Church, North Street, York
All Saints' Church is a Church of England parish church on North Street, York, North Yorkshire. The church is a Grade I listed building.
History
The earliest part of the church is the nave dating from the 12th century. The arcades date from ...
. His father was a labourer who worked at a local coal yard, by the Ouse, constantly replenished from the Yorkshire coalfield by barges, but later was a farmer in a small village to the north of York.
The neighbourhood was one of the poorest in the city, and was frequently in danger of flooding because of its proximity to the
River Ouse. Growing up, Snow experienced unsanitary conditions and contamination in his hometown. Most of the streets were unsanitary and the river was contaminated by runoff water from market squares, cemeteries and sewage.
From a young age, Snow demonstrated an aptitude for mathematics. In 1827, when he was 14, he obtained a medical apprenticeship with William Hardcastle in the area of
Newcastle-upon-Tyne
Newcastle upon Tyne (Received Pronunciation, RP: , ), or simply Newcastle, is a City status in the United Kingdom, city and metropolitan borough in Tyne and Wear, England. The city is located on the River Tyne's northern bank and forms the la ...
. In 1832, during his time as a surgeon-apothecary apprentice, he encountered
a cholera epidemic for the first time in
Killingworth
Killingworth, formerly Killingworth Township, is a town in North Tyneside, England.
Killingworth was built as a planned town in the 1960s, next to Killingworth Village, which existed for centuries before the Township. Other nearby towns an ...
, a coal-mining village. Snow treated many victims of the disease and thus gained experience. Eventually he adjusted to
teetotalism and led a life characterized by abstinence, signing an
abstinence pledge in 1835. Snow was also a vegetarian and tried to only drink distilled water that was “pure”.
Between 1832 and 1835 Snow worked as an assistant to a
colliery
Coal mining is the process of extracting coal from the ground. Coal is valued for its energy content and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron fro ...
surgeon, first in
Burnopfield
Burnopfield is a village in County Durham, in England. It is situated north of Stanley and Annfield Plain, close to the River Derwent and is 564 feet above sea level. There are around 4,553 inhabitants in Burnopfield. It is located 7 miles fro ...
, County Durham, and then in
Pateley Bridge,
West Riding of Yorkshire
The West Riding of Yorkshire is one of three historic subdivisions of Yorkshire, England. From 1889 to 1974 the administrative county County of York, West Riding (the area under the control of West Riding County Council), abbreviated County ...
. In October 1836 he enrolled at the
Hunterian school of medicine on
Great Windmill Street, London.
Career
In the 1830s, Snow's colleague at the
Newcastle Infirmary was surgeon
Thomas Michael Greenhow. The surgeons worked together conducting research on England's
cholera epidemics, both continuing to do so for many years.
In 1837, Snow began working at the
Westminster Hospital. Admitted as a member of the
Royal College of Surgeons of England
The Royal College of Surgeons of England (RCS England) is an independent professional body and registered charity that promotes and advances standards of surgical care for patients, and regulates surgery and dentistry in England and Wales. The ...
on 2 May 1838, he graduated from the
University of London
The University of London (UoL; abbreviated as Lond or more rarely Londin in post-nominals) is a federal public research university located in London, England, United Kingdom. The university was established by royal charter in 1836 as a degre ...
in December 1844 and was admitted to the
Royal College of Physicians
The Royal College of Physicians (RCP) is a British professional membership body dedicated to improving the practice of medicine, chiefly through the accreditation of physicians by examination. Founded by royal charter from King Henry VIII in 1 ...
in 1850. Snow was a founding member of the
Epidemiological Society of London which was formed in May 1850 in response to the cholera outbreak of 1849. By 1856, Snow and Greenhow's nephew,
Dr. E.H. Greenhow were some of a handful of esteemed medical men of the society who held discussions on this "dreadful scourge, the
cholera".
After finishing his medical studies in the
University of London
The University of London (UoL; abbreviated as Lond or more rarely Londin in post-nominals) is a federal public research university located in London, England, United Kingdom. The university was established by royal charter in 1836 as a degre ...
, he earned his MD in 1844. Snow set up his practice at 54 Frith Street in Soho as a surgeon and general practitioner. John Snow contributed to a wide range of medical concerns including
anaesthesiology. He was a member of the
Westminster Medical Society
The Westminster Medical Society was a London medical discussion group in existence from 1809 to 1850–1, when it merged into the Medical Society of London.
Its founders were Benjamin Brodie and Sir Charles Mansfield Clarke, Baronet. Initially t ...
, an organisation dedicated to clinical and scientific demonstrations. Snow gained prestige and recognition all the while being able to experiment and pursue many of his scientific ideas. He was a speaker multiple times at the society's meetings and he also wrote and published articles. He was especially interested in patients with respiratory diseases and tested his hypothesis through animal studies. In 1841, he wrote, ''On Asphyxiation, and on the Resuscitation of Still-Born Children'', which is an article that discusses his discoveries on the physiology of neonatal respiration, oxygen consumption and the effects of body temperature change.
In 1857, Snow made an early and often overlooked contribution to epidemiology in a pamphlet, ''On the adulteration of bread as a cause of
rickets''.
Anaesthesia
Snow's interest in
anaesthesia
Anesthesia is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), am ...
and breathing was evident from 1841 and beginning in 1843, he experimented with
ether
In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again b ...
to see its effects on respiration.
Only a year after ether was introduced to Britain, in 1847, he published a short work titled, ''On the Inhalation of the Vapor of Ether,'' which served as a guide for its use. At the same time, he worked on various papers that reported his clinical experience with anaesthesia, noting reactions, procedures and experiments. Within two years of ether being introduced, Snow was the most accomplished anaesthetist in Britain. London's principal surgeons suddenly wanted his assistance.
As well as ether, John Snow studied
chloroform
Chloroform, or trichloromethane, is an organic compound with formula C H Cl3 and a common organic solvent. It is a colorless, strong-smelling, dense liquid produced on a large scale as a precursor to PTFE. It is also a precursor to various re ...
, which was introduced in 1847 by
James Young Simpson, a Scottish obstetrician. He realised that chloroform was much more potent and required more attention and precision when administering it. Snow first realised this with Hannah Greener, a 15-year-old patient who died on 28 January 1848 after a surgical procedure that required the cutting of her toenail. She was administered chloroform by covering her face with a cloth dipped in the substance. However, she quickly lost pulse and died. After investigating her death and a couple of deaths that followed, he realized that chloroform had to be administered carefully and published his findings in a letter to ''The Lancet''.
John Snow was one of the first physicians to study and calculate dosages for the use of ether and chloroform as surgical
anaesthetic
An anesthetic (American English) or anaesthetic (British English; see spelling differences) is a drug used to induce anesthesia — in other words, to result in a temporary loss of sensation or awareness. They may be divided into ...
s, allowing patients to undergo surgical and
obstetric
Obstetrics is the field of study concentrated on pregnancy, childbirth and the postpartum period. As a medical specialty, obstetrics is combined with gynecology under the discipline known as obstetrics and gynecology (OB/GYN), which is a surgi ...
procedures without the distress and pain they would otherwise experience. He designed the apparatus to safely administer ether to the patients and also designed a mask to administer chloroform. Snow published an article on ether in 1847 entitled ''On the Inhalation of the Vapor of Ether''. A longer version entitled ''On Chloroform and Other Anaesthetics and Their Action and Administration'' was published posthumously in 1858.
Although he thoroughly worked with ether as an anaesthetic, he never attempted to patent it; instead, he continued to work and publish written works on his observations and research.
Obstetric anaesthesia
Snow's work and findings were related to both anaesthesia and the practice of childbirth. His experience with obstetric patients was extensive and used different substances including ether,
amylene and chloroform to treat his patients. However, chloroform was the easiest drug to administer. He treated 77 obstetric patients with chloroform. He would apply the chloroform at the second stage of labour and controlled the amount without completely putting the patients to sleep. Once the patient was delivering the baby, they would only feel the first half of the contraction and be on the border of unconsciousness, but not fully there. Regarding administration of the anaesthetic, Snow believed that it would be safer if another person that was not the surgeon applied it.
The use of chloroform as an anaesthetic for childbirth was seen as unethical by many physicians and even the
Church of England
The Church of England (C of E) is the established Christian church in England and the mother church of the international Anglican Communion. It traces its history to the Christian church recorded as existing in the Roman province of Britai ...
. However, on 7 April 1853,
Queen Victoria
Victoria (Alexandrina Victoria; 24 May 1819 – 22 January 1901) was Queen of the United Kingdom of Great Britain and Ireland from 20 June 1837 until her death in 1901. Her reign of 63 years and 216 days was longer than that of any previ ...
asked John Snow to administer chloroform during the delivery of her eighth child,
Leopold. He then repeated the procedure for the delivery of her daughter
Beatrice
Beatrice may refer to:
* Beatrice (given name)
Places In the United States
* Beatrice, Alabama, a town
* Beatrice, Humboldt County, California, a locality
* Beatrice, Georgia, an unincorporated community
* Beatrice, Indiana, an unincorporated ...
in 1857. This led to wider acceptance of obstetrical anaesthesia.
Cholera
Snow was a skeptic of the then-dominant
miasma theory that stated that diseases such as cholera and
bubonic plague
Bubonic plague is one of three types of plague caused by the plague bacterium ('' Yersinia pestis''). One to seven days after exposure to the bacteria, flu-like symptoms develop. These symptoms include fever, headaches, and vomiting, as ...
were caused by pollution or a noxious form of "bad air". The
germ theory of disease
The germ theory of disease is the currently accepted scientific theory for many diseases. It states that microorganisms known as pathogens or "germs" can lead to disease. These small organisms, too small to be seen without magnification, invade ...
had not yet been developed, so Snow did not understand the mechanism by which the disease was transmitted. His observation of the evidence led him to discount the theory of foul air. He first published his theory in an 1849 essay, ''On the Mode of Communication of Cholera'', followed by a more detailed treatise in 1855 incorporating the results of his investigation of the role of the water supply in the
Soho
Soho is an area of the City of Westminster, part of the West End of London. Originally a fashionable district for the aristocracy, it has been one of the main entertainment districts in the capital since the 19th century.
The area was develo ...
epidemic of 1854.
By talking to local residents (with the help of
Henry Whitehead), he identified the source of the outbreak as the public water pump on Broad Street (now
Broadwick Street). Although Snow's chemical and microscope examination of a water sample from the
Broad Street pump did not conclusively prove its danger, his studies of the pattern of the disease were convincing enough to persuade the local council to disable the well pump by removing its handle (
force rod). This action has been commonly credited as ending the outbreak, but Snow observed that the epidemic may have already been in rapid decline:
Snow later used a
dot map to illustrate the cluster of cholera cases around the pump. He also used statistics to illustrate the connection between the quality of the water source and cholera cases. He showed that homes supplied by the
Southwark and Vauxhall Waterworks Company, which was taking water from sewage-polluted sections of the
Thames
The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the ...
, had a cholera rate fourteen times that of those supplied by
Lambeth Waterworks Company, which obtained water from the upriver, cleaner
Seething Wells. Snow's study was a major event in the history of public health and geography. It is regarded as the founding event of the science of
epidemiology
Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population.
It is a cornerstone of public health, and shapes policy decisions and evide ...
.
Snow wrote:
Researchers later discovered that this public well had been dug only from an old
cesspit, which had begun to leak faecal bacteria. The cloth nappy of a baby, who had contracted cholera from another source, had been washed into this cesspit. Its opening was originally under a nearby house, which had been rebuilt farther away after a fire. The city had widened the street and the cesspit was lost. It was common at the time to have a cesspit under most homes. Most families tried to have their raw sewage collected and dumped in the Thames to prevent their cesspit from filling faster than the sewage could decompose into the soil.
Thomas Shapter had conducted similar studies and used a point-based map for the study of cholera in
Exeter
Exeter () is a city in Devon, South West England. It is situated on the River Exe, approximately northeast of Plymouth and southwest of Bristol.
In Roman Britain, Exeter was established as the base of Legio II Augusta under the personal c ...
, seven years before John Snow, although this did not identify the water supply problem that was later held responsible.
Political controversy
After the cholera epidemic had subsided, government officials replaced the Broad Street pump handle. They had responded only to the urgent threat posed to the population, and afterward they rejected Snow's theory. To accept his proposal would have meant indirectly accepting the fecal-oral route of disease transmission, which was too unpleasant for most of the public to contemplate.
It was not until 1866 that
William Farr, one of Snow's chief opponents, realised the validity of his diagnosis when investigating another outbreak of cholera at
Bromley by Bow
Bromley, commonly known as
Bromley-by- Bow, is a district in the London Borough of Tower Hamlets in East London, located on the western banks of the River Lea, in the Lower Lea Valley in East London.
The area is distinct from Bow, which ...
and issued immediate orders that unboiled water was not to be drunk.
Farr denied Snow's explanation of how exactly the contaminated water spread cholera, although he did accept that water had a role in the spread of the illness. In fact, some of the statistical data that Farr collected helped promote John Snow's views.
Public health officials recognise the political struggles in which reformers have often become entangled. During the Annual Pumphandle Lecture in England, members of the John Snow Society remove and replace a pump handle to symbolise the continuing challenges for advances in public health.
Personal life
Snow became a
vegetarian
Vegetarianism is the practice of abstaining from the consumption of meat ( red meat, poultry, seafood, insects, and the flesh of any other animal). It may also include abstaining from eating all by-products of animal slaughter.
Vegetaria ...
at the age of 17 and was a
teetotaller.
[Mather, J. D. (2004). ''200 Years of British Hydrogeology''. London: The Geological Society. p. 48. ] He embraced an
ovo-lacto vegetarian diet by supplementing his vegetables with dairy products and eggs. On this diet he excelled at swimming.
He later became a
vegan
Veganism is the practice of abstaining from the use of animal product—particularly in diet—and an associated philosophy that rejects the commodity status of animals. An individual who follows the diet or philosophy is known as a vegan. ...
. In the mid-1840s, his health deteriorated and he suffered a renal disorder which he attributed to his vegan diet so he took up meat-eating and drinking wine. He continued drinking pure water (via boiling) throughout his adult life. He never married.
In 1830, Snow became a member of the
temperance movement
The temperance movement is a social movement promoting temperance or complete abstinence from consumption of alcoholic beverages. Participants in the movement typically criticize alcohol intoxication or promote teetotalism, and its leaders emph ...
. In 1845, he became a member of York Temperance Society.
After his health declined it was only about 1845 that he consumed a little wine to aid digestion.
Snow lived at 18
Sackville Street, London, from 1852 to his death in 1858.
[''JOHN SNOW'S HOMES''.]
UCLA Department of Epidemiology, 2014. Retrieved 6 June 2014.
Snow suffered a stroke while working in his London office on 10 June 1858. He was 45 years old at the time. He never recovered, dying six days later on 16 June 1858. He was buried in
Brompton Cemetery
Brompton Cemetery (originally the West of London and Westminster Cemetery) is a London cemetery, managed by The Royal Parks, in West Brompton in the Royal Borough of Kensington and Chelsea. It is one of the Magnificent Seven cemeteries. Es ...
.
Legacy and honours
* A plaque commemorates Snow and his 1854 study in the place of the water pump on Broad Street (now Broadwick Street). It shows a water pump with its handle removed. The spot where the pump stood is covered with red granite.
* A public house nearby was named "The John Snow" in his honour.
[
]
* The John Snow Society is named in his honour, and the society regularly meets at The John Snow pub. An annual Pumphandle Lecture is delivered each September by a leading authority in contemporary public health.
* His grave in
Brompton Cemetery
Brompton Cemetery (originally the West of London and Westminster Cemetery) is a London cemetery, managed by The Royal Parks, in West Brompton in the Royal Borough of Kensington and Chelsea. It is one of the Magnificent Seven cemeteries. Es ...
, London, is marked by a funerary monument.
* In York a
blue plaque
A blue plaque is a permanent sign installed in a public place in the United Kingdom and elsewhere to commemorate a link between that location and a famous person, event, or former building on the site, serving as a historical marker. The term i ...
on the west end of the Park Inn, a hotel in North Street, commemorates John Snow.
* Together with fellow pioneer of anaesthesia
Joseph Thomas Clover
Joseph Thomas Clover (28 February 1825; baptised 7 May 1825 – 27 September 1882) was an English doctor and pioneer of anaesthesia. He invented a variety of pieces of apparatus to deliver anaesthetics including ether and chloroform safely and ...
, Snow is one of the
heraldic supporters of the
Royal College of Anaesthetists
The Royal College of Anaesthetists (RCoA) is the professional body responsible for the specialty of anaesthesia throughout the United Kingdom. It sets standards in anaesthesia, critical care, pain management, and for the training of anaest ...
.
* The
Association of Anaesthetists of Great Britain and Ireland
The Association of Anaesthetists, in full the Association of Anaesthetists of Great Britain and Ireland (AAGBI), is a professional association for anaesthetists in the United Kingdom and Ireland.
It was founded by Dr Henry Featherstone in 193 ...
awards The John Snow Award, a bursary for undergraduate
medical students
A medical school is a tertiary educational institution, or part of such an institution, that teaches medicine, and awards a professional degree for physicians. Such medical degrees include the Bachelor of Medicine, Bachelor of Surgery (MBBS, M ...
undertaking research in the field of anaesthesia.
* Despite reports that Snow was awarded a prize by the
Institut de France
The (; ) is a French learned society, grouping five , including the Académie Française. It was established in 1795 at the direction of the National Convention. Located on the Quai de Conti in the 6th arrondissement of Paris, the institute ...
for his 1849 essay on cholera, a 1950 letter from the Institut indicates that he received only a nomination for it.
* In 1978 a public health research and consulting firm,
John Snow, Inc
John Snow, Inc. (JSI) is a global public health consulting organization. JSI was founded in 1978 by Joel Lamstein and Norbert Hirschhorn. In 2022, Margaret Crotty was appointed as CEO and president, succeeding founder Lamstein. The firm is based ...
, was founded.
* In 2001 the
John Snow College was founded on the
University of Durham
, mottoeng = Her foundations are upon the holy hills ( Psalm 87:1)
, established = (university status)
, type = Public
, academic_staff = 1,830 (2020)
, administrative_staff = 2,640 (2018/19)
, chancellor = Sir Thomas Allen
, vice_ch ...
's Queen's Campus in
Stockton-on-Tees.
* In 2009, the John Snow lecture theatre was opened by
Anne, Princess Royal
Anne, Princess Royal (Anne Elizabeth Alice Louise; born 15 August 1950), is a member of the British royal family. She is the second child and only daughter of Queen Elizabeth II and Prince Philip, Duke of Edinburgh, and the only sister of Kin ...
, at the
London School of Hygiene & Tropical Medicine
The London School of Hygiene and Tropical Medicine (LSHTM) is a public university, public research university in Bloomsbury, central London, and a constituent college, member institution of the University of London that specialises in public h ...
.
* In 2013 ''
The Lancet
''The Lancet'' is a weekly peer-reviewed general medical journal and one of the oldest of its kind. It is also the world's highest-impact academic journal. It was founded in England in 1823.
The journal publishes original research articles, ...
'' printed a correction of its brief obituary of Snow, originally published in 1858: "The journal accepts that some readers may wrongly have inferred that ''The Lancet'' failed to recognise Dr Snow's remarkable achievements in the field of epidemiology and, in particular, his visionary work in deducing the mode of transmission of epidemic cholera."
* In 2016, Katherine Tansley published a fictionalised account based on Snow's activities, in her historical novel ''The Doctor of Broad Street'' (Troubadour Books).
* In 2017 York Civic Trust erected a memorial to John Snow in the form of a pump with its handle removed, a blue plaque and an interpretation board, in North Street Gardens, York, close to his birthplace.
* The 2019 TV series ''
Victoria'' in the third-season episode "Foreign Bodies", John Snow meets Queen Victoria (no date mentioned but this happened in 1854) and, with the Queen's help, has the local authorities remove the Broad Street pump handle. (They did not mention his 1853 use of chloroform on the Queen for childbirth.)
See also
*
William Budd, recognized that cholera was contagious
* ''
The Ghost Map'', book on cholera epidemiology
*
Florence Nightingale
Florence Nightingale (; 12 May 1820 – 13 August 1910) was an English social reformer, statistician and the founder of modern nursing. Nightingale came to prominence while serving as a manager and trainer of nurses during the Crimean War, i ...
, founder of modern nursing
*
Filippo Pacini
Filippo Pacini (25 May 1812 – 9 July 1883) was an Italian anatomist, posthumously famous for isolating the cholera bacterium '' Vibrio cholerae'' in 1854, well before Robert Koch's more widely accepted discoveries 30 years later.
Pacini was ...
, isolated cholera
*
Joseph Bazalgette, sewer engineer for London
References
Sources
* Hempel, Sandra (2006). ''The Medical Detective: John Snow, Cholera, and the Mystery of the Broad Street Pump.'' Granta Books.
*
Johnson, Steven (2006). ''
The Ghost Map: The Story of London's Most Terrifying Epidemic – and How it Changed Science, Cities and the Modern World''.
Riverhead Books.
*
Körner, T. W. (1996). ''The Pleasures of Counting'', chapter 1.
Cambridge University Press
Cambridge University Press is the university press of the University of Cambridge. Granted letters patent by Henry VIII of England, King Henry VIII in 1534, it is the oldest university press in the world. It is also the King's Printer.
Cambr ...
.
* Morris, Robert D. (2007). ''The Blue Death''.
Harper Collins.
*
Shapin, Steven (6 November 2006)
lectronic version. ''
The New Yorker
''The New Yorker'' is an American weekly magazine featuring journalism, commentary, criticism, essays, fiction, satire, cartoons, and poetry. Founded as a weekly in 1925, the magazine is published 47 times annually, with five of these issue ...
''. Retrieved 10 November 2006
*
Tufte, Edward (1997). ''Visual Explanations'', chapter 2.
Graphics Press.
Further reading
*
External links
"On the Mode of Communication of Cholera" by John Snow, M.D. (1st ed., 1849)"On the Mode of Communication of Cholera" by John Snow, M.D. ("2nd edition, much enlarged", includes cholera map opposite p. 45)Short narrative film about John SnowJohn Snow Society* Interactive versions of the John Snow's Map of Board Street Cholera Outbreak
*
umapper*
John Snow’s cholera analysis data in modern GIS formatsPredictionX: John Snow and the Cholera Epidemic of 1854 (a Harvard/edX MOOC)The John Snow Archive and Research Companion
{{DEFAULTSORT:Snow, John
Public health in the United Kingdom
1813 births
1858 deaths
English anaesthetists
Burials at Brompton Cemetery
Cholera
19th-century English medical doctors
Alumni of the University of London
Alumni of Westminster Hospital Medical School
English temperance activists
British public health doctors
People from York
Medical doctors from Yorkshire
Water supply and sanitation in London
19th-century English writers
19th-century English male writers
Environmental health practitioners
British epidemiologists
Physicians of the Westminster Hospital
Spatial epidemiology