John Dalton

About this figure

John Dalton (1766-1844) was an English chemist, physicist, and meteorologist raised in a Quaker family in Cumberland, best remembered for developing the modern atomic theory of matter. Largely self-taught after a limited formal education, Dalton spent most of his working life as a teacher in Manchester while pursuing scientific research independently.

Building on the observation that elements combine in fixed, simple whole-number ratios, Dalton proposed that each chemical element consists of atoms of a single, characteristic weight, and that chemical compounds form through combinations of these atoms in fixed proportions. He set out this theory, along with tables of relative atomic weights he had calculated, in A New System of Chemical Philosophy, published in installments between 1808 and 1827. Dalton also conducted extensive research on gases, formulating what is now called Dalton's law of partial pressures, describing how the pressures of gases in a mixture combine, and he kept detailed daily meteorological records for decades.

He is additionally credited with the first scientific description of color blindness, a condition he himself had and which was for a time called Daltonism in his honor; his account, based partly on his own vision, remains a landmark in the study of the disorder. Dalton lived modestly throughout his life, continuing to teach and take his own weather readings into old age, and he died in Manchester in 1844.

Written by Epoch Voices. Not the figure’s own words.