John Dalton

John Dalton, 1766-1844, English chemist and Fellow of the Royal Society.

Dalton was the first to provide a scientific description of color blindness (1794), a condition from which he suffered and which was long called "Daltonism." Dalton recorded over 200,000 observations of the atmosphere in his notebooks, and studied mixed gases and the expansion of gases under heat; Dalton's Law is still used to describe the law of partial pressures in chemistry. This work led him to his most important theoretical contribution to chemistry, a scientifically grounded atomic theory of matter. He lectured on his discoveries in 1803, and published them at greater length in A New System of Chemical Philosophy in 1808.