John Scott Haldane CH FRS (May 3, 1860 – March 14/March 15, 1936) was a Scottish physiologist famous for intrepid self-experimenting which led to many important discoveries about the human body and the nature of gases. He also used his son J. B. S. Haldane as a guinea pig, even when he was quite young. John Haldane locked himself in sealed chambers breathing lethal cocktails of gases while recording their effect on his mind and body. He visited the scenes of many mining disasters and investigated their causes. When the Germans used poison gas in World War I Haldane went to the front at the request of British secretary of state, Lord Kitchener and attempted to identify the gases being used. One outcome of this was his invention of the first gas mask [1] His son, J.B.S. Haldane became equally famous, both by extending his father's interest in diving and as a key figure in the development of the modern evolutionary synthesis.

John Scott Haldane (* 3. Mai 1860 in Edinburgh; † 15. März 1936 in Oxford) war ein schottischer Physiologe und gilt als Begründer des methodischen Holismus.

John Scott Haldane (3 Mai 1860 - 15 Mars 1936) était un physiologiste irlandais spécialisé dans la respiration.

John Scott Haldane, född 3 maj 1860, död 14 mars/15 mars 1936

John Scott Haldane (ur. 3 maja 1860, zm. 14/15 marca 1936) był szkockim lekarzem, wykładowcą na uniwersytecie w Glasgow, Oksfordzie i Birmingham.