John Scott Haldane was born in Edinburgh on May 3 1860 to Robert Haldane, Writer to the Signet of Cloanden, and Mary Elizabeth. He attended Edinburgh University and the Friedrich Schiller University of Jena, before graduating in medicine at Edinburgh in 1884. He was then appointed Demonstrator in Physiology at University College, Dundee, where he investigated the composition of the air in dwellings and schools.

In 1887, he moved to Oxford, joining his uncle, John Burdon-Sanderson, who was Waynflete Professor of Physiology, as a demonstrator. Haldane studied the suffocative gases occurring in coal mines and wells, exposing their dependence on spontaneous oxidation processes that could take place in the coal and soil. Further work shed light on the physiological action of carbon monoxide, and in due course he submitted an important report to the Home Secretary in 1896, showing the causes of death in colliery explosions and underground fires. Haldane’s work formed a basis on which to develop measures to prevent the danger. As a result of his research he became associated with the mining profession, an association he maintained his entire life.

In 1901, Haldane was elected a Fellow of New College, Oxford. His paper on the regulation of lung ventilation, developed in collaboration with John Gillies Priestley, was published in the Journal of Physiology in 1905. In his continuing research in pure physiology, Haldane investigated the impacts of oxygen deficiency and muscular exercise on breathing.

From 1907 to 1913, Haldane was Reader in Physiology at Oxford. In 1911, along with C. G Douglas, with whom he worked in the Oxford Laboratory of Physiology, led an expedition to Pike’s Peak, Colorado, to examine the effects of low atmospheric pressure on respiration. They stayed at the summit house of Pike’s Peak (14,110 feet above sea level), in which they built a laboratory and investigated the process of acclimatisation of breathing to high altitude oxygen levels. Pioneering Scientist Mabel Fitzgerald was also a member of this expedition. Their discoveries revolutionised current ideas about respiration.

During the First World War, Haldane was asked to identify the type of poison gas introduced by the Germans and its effects. Haldane found it was chlorine. In order to protect the soldiers, Haldane designed a portable oxygen administration apparatus for use in the field, the first gas mask. He also demonstrated the value of oxygen in treating soldiers when they were gassed.

Haldane was elected Fellow of the Royal Society in 1897, a Royal Medallist of the society in 1916, Copley Medallist in 1934, and in 1928 he was appointed Companion of Honour for his scientific work in connection with industrial disease. He died in Oxford in March 1936, shortly after returning from a visit to Persia, where he had been investigating cases of heat stroke in the oil refineries.