The modern doctrine of the exchange of gases in respiration began with the discovery of oxygen by Scheele, Priestley, and Lavoisier, and the rediscovery of carbon dioxide by Joseph Black. Although these contributions are chemical in nature, each scientist, except Scheele, had received medical training. Black, in addition to his contributions to chemistry and medicine, is credited with major discoveries in physics, especially for his discussions of "specific heat," "capacity for heat," and "latent heat."
Joseph Black, of Scottish descent, was born at Bordeaux, France, in 1728, where his father, a native of Belfast, was a wine merchant.1 Joseph spent some years in school in Ireland, then attended Glasgow University, and studied under William Cullen, professor of anatomy and lecturer on chemistry. Black went to Edinburgh in 1750 for his medical studies. It was there that, as a medical student, while pondering the origin of kidney stones, he began