1748-1795

Irish physician and physicist who performed the first experiments to determine the specific heats of gases. Crawford believed the chemical changes in air brought about by respiration also altered air's heat capacity or specific heat. According to his application of William Irvine's theory of heat capacities, inhaled air had a greater specific heat than exhaled air, with the difference being transferred to and thus being the source of the body's heat. Irvine's theory of capacities was later shown to be untenable.