John Scott Haldane, a British physiologist, obtained the Master of Arts (MA) degree from the University of Edinburgh in 1879, then qualified as a licentiate of the Royal College of Physicians and Surgeons of Edinburgh in 1883, and was awarded the degree Bachelor of Medicine (MB) by the University of Edinburgh in 1885. After a short period as a demonstrator of physiology at the University College, Dundee, he moved to the University of Oxford where he was appointed as demonstrator in the Department of Physiology in January 1887. He became a lecturer there in 1894, and a reader in physiology in 1907. In 1913 he resigned his post to become director of a mining research laboratory near Doncaster. He was appointed as an honorary professor at the University of Birmingham in 1923 and served as president of the Institute of Mining Engineers from 1924 to 1928. During the Anglo-Boer War (1899-1902) he wrote a brief account of "The concentration camps" for the South Africa Conciliation Committee (published as one of its Leaflets and Pamphlets, No. 85, 1901).
In his research Haldane focussed mainly on the physiology of respiration. Among others he studied the physiological action of carbon monoxide; determined in 1905 that respiration is regulated mainly by the concentration of carbon dioxide in the blood; and in 1901 introduced an improved method of blood gas analysis. As a philosopher he was an idealist and opponent of scientific reductionism. He applied his research particularly to conditions in mines and wrote many papers and reports on the quality of air in mines, dust inhalation, the health of mine workers, and industrial health in general. In 1901 he became a co-founder of the Journal of Hygiene and served as one of its editors. His more comprehensive publications included Methods of air analysis (1912, and later editions to 1935), Mechanism, mind and personality (1913, 1921, 1929), Organism and environment as illustrated by the physiology of breathing (1917), Respiration (1922, 1935), The sciences and philosophy (1928), Gases and liquids; a contribution to modern physics (1928), and Materialism (1932).
Haldane was an honorary member of the Chemical, Metallurgical and Mining Society of South Africa for over 20 years, until his death. In 1918 he wrote a paper on "The effects of dust inhalation" for the society's Journal. He visited South Africa in 1929 and addressed several meetings of the society on problems connected with mine ventilation and the prevention of silicosis. He showed a keen desire to provide more comfortable working conditions in the local mining industry and in general tried to improve the conditions for every worker that had to breathe an abnormal atmosphere, whether in the mines, in factories on the surface, or under water. During his visit he was awarded an honorary Doctor of Science degree in engineering by the University of the Witwatersrand.