John Dalton(redirected from Dalton's atomic hypothesis)
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Dalton, John(dôl`tən), 1766–1844, English scientist. He revived the atomic theory (see atomatom
[Gr.,=uncuttable (indivisible)], basic unit of matter; more properly, the smallest unit of a chemical element having the properties of that element. Structure of the Atom
..... Click the link for more information. ), which he formulated in the first volume of his New System of Chemical Philosophy (2 vol., 1808–27). He had already applied the concept to a table of atomic weights (1803), in a paper (1805) on the absorption of gases, and in developing his famous law of partial pressures, known also as Dalton's lawDalton's law
[for John Dalton], physical law that states that the total pressure exerted by a homogeneous mixture of gases is equal to the sum of the partial pressures of the individual gases.
..... Click the link for more information. . His interest in weather conditions led him to keep daily records from 1787 and to write Meteorological Observations and Essays (1793). Dalton, himself afflicted with color blindness, investigated (c.1794) the condition, known also as Daltonism. From 1793 he taught mathematics and physical sciences at New College, Manchester. He was a member of the Royal Society (from 1822) and in 1825 received its medal for his work on the atomic theory.
See study by A. Thackray (1972).
Born Sept. 6, 1766, in Eaglesfield, England; died July 27, 1844, in Manchester. English physicist and chemist. Member of the Royal Society of London (1822).
The son of a weaver, Dalton, who was self-educated, taught mathematics in Kendal and Manchester. He was a member (from 1794), secretary (from 1800), and chairman (from 1817) of the Manchester Literary and Philosophical Society. While studying the properties of gas mixtures, he discovered the law of partial gas pressures (1801) and the dependence of the dissolution of gases on their partial pressures (1803). He investigated the dependence of the evaporation of a liquid on pressure, temperature, and other factors. In 1802 he established (somewhat ahead of J. Gay-Lussac and independently of J. Charles) that at constant pressure all gases expand identically when temperature is increased identically. Dalton wrote fundamental works on chemical atomics. In 1794 he was the first to describe a visual defect (from which he himself suffered) that came to be called Daltonism (color blindness).
WORKSSbornik izbrannykh rabot po atomistike. Leningrad. 1940. (Translated from English. 1802–10.)
REFERENCESKedrov, B.M. Atomistika Dal’tona. Moscow-Leningrad. 1949.
Henry. W. C. Memoirs of the Life and Scientific Researches of John Dalton. London, 1854.
Smith, R. Memoirs of John Dalton and History of the Atomic Theory up to His Time. London, 1956.