1-158-722 - Oxford Science Archive/Heritage Images

John Dalton, English chemist, c1834 (1902). As a Quaker, Dalton (1766-1844) could not attend an English university, so supported himself by teaching. He studied gases, and in 1808 proposed his atomic theory. In 1794 he was the first to describe colour blindness (Daltonism) from which both he and his brother suffered. He kept a meteorological diary for many years and amassed some 200,000 observations.