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Behind the picture: Leonard Hill and the divers

by Guest Author on 13 Aug 2014

Leonard Hill wasn’t the type of researcher to confine his research to the laboratory, as this picture shows. Here Julie Clayton, author of a new history of the MRC National Institute for Medical Research, takes a look behind this picture to a man concerned with the health and wellbeing of everyone from slum-dwelling children to parliamentarians.

Leonard Hill with a diver sitting either side

Leonard Hill on a boat during a diving experiment (Image copyright: The Physiological Society, sourced from the Wellcome Library)

 This photo, taken circa 1925, shows Leonard Hill ― mustachioed and dressed somewhat inappropriately for a day on the water ― alongside two of his research subjects.

As well as wearing these cumbersome suits, deep-water divers at the time often suffered the painful and dangerous condition of “the bends” when they ascended too quickly to the surface.

It was physiologist Hill who found that the drop in external pressure during ascent led to the formation of tiny bubbles of nitrogen gas in the blood. He did experiments on frogs to demonstrate that the bubbles dissolve again into the blood stream upon recompression. His work led to recommendations for a slow and steady decompression for divers as a remedy.

Hill devoted his life and work to people’s physical wellbeing both at home and in the workplace.

He showed an inclination towards scientific study from an early age, experimenting at his home in Tottenham, London, at the age of four, by “dropping the family cat out of the window to see if it would really fall on its feet” (1).

He studied medicine to please his father, but after obtaining his degree he switched to physiological research. He was Professor of Physiology at the London Hospital, then Director of the Department of Applied Physiology at the NIMR. He made his first mark by devising the “Hill sign”, in which a difference between blood pressure of the arm and leg was found to indicate the presence of aortic regurgitation ― a serious condition in which blood leaks the wrong way through the aortic valve.

From the slums to Parliament

However, it was work on the importance of sunshine, outdoor exercise and fresh air that made Hill a household name in Britain, suggesting that the modern obsession with diet, exercise and fresh air may not be quite so modern after all.

He was deeply concerned about the poor health of city slum dwellers living among the smoke from factories and homes. Besides causing respiratory problems, the resultant haze could block out up to a half of the sun’s rays, Hill estimated.

He was also concerned about working conditions, telling The Daily Chronicle newspaper in 1925 of his concerns about the citizen “Shutting himself up, as he does nearly all day, in close rooms, while engaged in sedentary occupations, such bright sunshine as does come to him is filtered through glass, and thus robbed of its ultra-violet rays.”

Hill also advocated better ventilation for those working indoors. Through the invention of an instrument known as the kata-thermometer, he provided an objective measure of the “cooling power” of air movement. This was used to monitor workplace conditions across the UK, including the House of Commons where Hill was concerned that “cold feet and stuffy heads result ― just the wrong conditions for legislators” (2).

Hill’s interest in the need for fresh air and outdoor exercise may have been informed by his own health problems ― a major episode of tuberculosis forced him to take refuge on the coast of Dorset in 1916. Once back in good health, he led by example, swimming all year round in a forest pool at Epping Forest near his home in Loughton, Essex. Hill retired from NIMR in 1930 to give more time to his hobbies of painting and writing children’s fairy stories.

Julie Clayton


(1)  Hill, AB and Hill, B. The Life of Sir Leonard Erskine Hill (1862-1952)Proc R Soc Med. Mar 1968; 61(3): 307–316

(2)  Health and Environment, by Leonard Hill and Argyll Campbell. London. Edward Arnold & Co. 1925.



It’s an interesting story article and shows that how much curious he was to conduct an experimental research outside the laboratory.

author avatar by MUHAMMAD SAKHAWAT on 16-Aug-2014 07:21

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