Henry Barcroft was professor of physiology at St Thomas’s Hospital Medical School, London. He came from a distinguished Irish Quaker family and spent his childhood in an atmosphere steeped in academic science; his father was Sir Joseph Barcroft, a charismatic scientist who became professor of physiology at Cambridge. His mother, Mary ‘Minnie’ Ball, was the daughter of Sir Robert Ball, one time Astronomer Royal of Ireland who later became Lowndean professor of astronomy and geometry at Cambridge. Barcroft became familiar with the famous names who visited the family home and his father’s laboratories.
He was educated at Marlborough College and King’s College, Cambridge, where, like his father, he graduated with first class honours in both parts of the natural sciences tripos. He subsequently became a research student. It was E H Starling [Munk’s Roll, Vol.IV, p.397] who, while visiting Cambridge in 1925 to talk about his heart-lung preparation, stimulated Barcroft’s interest in the circulation.
In 1932, after clinical training at St Mary’s Hospital, London, Barcroft was appointed as a lecturer in physiology at University College, London. Barcroft devised a mechanical stromuhr to measure blood flow. It gave moment to moment readings, unlike most contemporary methods that averaged flow over longish periods. He used the stromuhr to study aortic flow changes in dogs and was the first to show the characteristic initial drop in cardiac output followed by the spike and plateau phase in response to intravenous adrenaline infusions.
In 1935 he moved to the Dunville chair of physiology at Queen’s University, Belfast. Despite a heavy teaching load and inadequate research facilities, he revitalized the department by attracting a series of bright researchers and began a productive series of studies on the human peripheral circulation. With Otto Edholm [Munk’s Roll, Vol.VIII, p.141] he developed the techniques of ‘venous occlusion plethysmography', a means of measuring blood flow in limbs. This was used to determine the roles of the sympathetic nervous fibres in the constriction and dilatation of the blood vessels of skin and muscle.
In 1948 Henry Barcroft was appointed to the chair of physiology at St Thomas’s Hospital. He maintained his interest in the human circulation and again revitalized the department by attracting young research workers. With colleagues from St Thomas’s and elsewhere, he studied the effects of rhythmic contractions, catecholamines and acute sympathectomy on muscle flow and the mechanism of functional hyperaemia. Some of this work was written up with H J C Swan as the first monograph of the Physiological Society series (Sympathetic control of human blood vessels, London, Arnold, 1953). It subsequently became a classic.
There were many reasons for Henry Barcroft’s success in research. He was remarkably energetic and was relentlessly curious about phenomena he did not understand. He was also fortunate to have inherited his intelligence, intellectual integrity and ability to find simple and inexpensive ways of overcoming problems from his scientist father. This meant he could improvise when faced with difficult technical problems.
He was also fortunate to have been educated in a scientific environment at University College greatly influenced by the character and style of the charismatic Sir William Bayliss. Thus he could simplify complex phenomena, breaking them down into individual components that could be tested. His concepts became understandable as he stripped away the unnecessary detail. It made him a gifted teacher.
Perhaps his most endearing characteristic was his ability to bring out aptitudes in young people. His bubbling enthusiasm could awaken in others an excitement and enthusiasm comparable to his own.
Henry Barcroft’s scientific productivity is a telling riposte to those who complain that they cannot do research since they have too much teaching and too little financial support. It also rebuts those who argue that good research is only possible when large numbers of scientists are gathered together. On the contrary, his life and work shows that much can be achieved by people prepared to make the most of their opportunities.
A lecture celebrating Henry Barcroft’s contribution to his subject and the Sherrington School of Physiology was given at a meeting of the Physiological Society at St Thomas’s Hospital in November 1997. Happily, he was there to enjoy it, sitting in the front row. He was to die nine weeks later, following a stroke.
Ian C Roddie
[The Guardian 4 Feb 1998; The Times 5 Feb 1998; The Daily Telegraph 7 Mar 1998; The Independent 19 Jan 1998]