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John Dalton
1766 – 1844

British chemist and physicist who developed the atomic theory of matter and hence is known as one of the fathers of modern physical science.

Early Life

John Dalton was born September 6, 1766 at Eaglesfield, near Cockermouth in the Lake District of Cumberland, Great Britian.1, 5 His father, Joseph Dalton, was a weaver in poor circumstances, who, with hiswife (Deborah Greenup), belonged to the Society of Friends; they had three children; Jonathan, John and Mary.7

John received his early education from his father and from John Fletcher, teacher of the Quaker school at Pardshow Hall in Eaglesfield.3, 7 John Fletcher, the master, was a superior man who did not use the rod to hammer in learning. He provided John with a superb background andlifelong quest for knowledge.3 Upon the retirement of Fletcher in 1778, when John Dalton was only 12 years old, he took charge of the Quaker school in Cumberland and two years later taught with his brother at a school in Kendal, where he was to remain for 12 years.1 This youthful venture was not successful, the amount he received in fees being only about five shillings a week, and after two years hetook to farm work. In 1781 he left his native village to become assistant to his cousin George Bewley, who kept a school at Kendal. There he passed the next twelve years, becoming in 1785, through the retirement of his cousin, joint manager of the school with his elder brother Jonathan. About 1790 he seems to have thought of taking up law or medicine, but his projects met with no encouragementfrom his relatives and he remained at Kendal till, in the spring of 1793, he moved to Manchester as a tutor at New College where he spent the rest of his life. It was here that John would rise above his country schoolteacher background to do his greatest work.3

In the early days of his teaching, Dalton's way of life was influenced by a wealthy Quaker, Elihu Robinson, a capable meteorologist andinstrument maker, who interested him in the problems of mathematics and meteorology.1, 5 During his life, Dalton was fascinated by the earth’s atmosphere.5 His first scientific work, which he began in 1787 and continued until the end of his life, was to keep a diary - which was ultimately to contain 200,000 entries - of meteorological observations recording the changeable climate of the lakedistrict in which he lived.1, 2 He then became interested in preparing collections of botanical and insect species. Stimulated by a spectacular aurora borealis display in 1788, he began observations about aurora phenomena - luminous, sometimes colored displays in the sky caused by electrical disturbances in the atmosphere.

Along with his other researches he also became interested in colorblindness, a condition that John Dalton and his brother, Jonathan, shared. In 1794 he was elected a member of the Manchester Literary and Philosophical Society, and a few weeks after election he communicated his first paper on Extraordinary facts relating to the vision of colors, in which he gave the earliest account of the optical peculiarity known as Daltonism or color-blindness. In his essay,Dalton had postulated that deficiency in color perception was caused by discoloration of the liquid medium of the eyeball and summed up its characteristics as observed in himself and others.1, 5, 7 Although Dalton's theory lost credence in his own lifetime, the meticulous, systematic nature of his research was so broadly recognized that Daltonism became a common term for color blindness.

These areonly some of the subjects on which he wrote essays that he read before the Philosophical Society: others included such topics as the barometer, thermometer, hygrometer, rainfall, the formation of clouds, evaporation and distribution and character of atmospheric moisture, including the concept of the dew point.1

Contributions to Nuclear Science

An indefatigable investigator or researcher,...