Dalton, JOHN, chemist and physicist, was born 6th September 1766, at Eaglesfield, near Cocker-mouth, in Cumberland, and was the son of a Quaker weaver. He received his early education at a
Quaker school in his native place, and, after 1781, in a boarding-school kept by a relative in Kendal, of which three years later he and a brother became the proprietors. Here his love of mathematical and physical studies was first developed. He wrote several mathematical essays, and in 1787 commenced a journal of meteorological observations, which he continued throughout his whole life, recording in all 200,000 observations. He collected butterflies, and gathered a great hortus siccus and herbarium. In 1793 he was appointed teacher of mathematics and the physical sciences in New College, Manchester: after the removal of the college to York in 1799, he supported himself in Manchester by private tuition. In 1803 he lectured at the Royal Institution. His Meteorological Observations (1793), dealing largely with auroras, contained the germs of many of his future discoveries. In 1794 he first described the phenomena of colour-blindness, observed by him in his own case and that of his brother, and often called Daltonism. In 1808-10 he published his New System of Chemical Philosophy, to which he added the first part of a second volume in 1827. In 1817 he was appointed president of the Manchester Philosophical Society. He was also a member of the Royal Society, and an associate of the Paris Academy, and of several other foreign societies. In 1833 he received a pension of £150, afterwards raised to £300. In the same year Dalton's friends and fellow-townsmen collected £2000, to raise a statue to his honour, which was executed by Chantrey, and placed at the entrance of the Royal Institution in Manchester. Oxford gave him its D.C.L., and Edinburgh, LL.D. He was twice a vice-president of the British Association. In 1837 he had a shock of paralysis, and he died, universally respected, at Manchester, July 27, 1844. His chief physical researches were on the constitution of mixed gases, on the force of steam, on the elasticity of vapours, and on the expansion of gases by heat. In chemistry, he distinguished himself by his development of the atomic theory, as also by his researches on the absorption of gases by water, on carbonic acid, carburetted hydrogen, &c. Dalton was unquestionably one of the greatest chemists that any country has produced. Profound, patient, and intuitive, he had precisely the faculties requisite for a great scientific discoverer. His atomic theory elevated chemistry into a science. In his habits, Dalton was simple; in manners, grave and reserved, but kindly, and distinguished by his truthfulness and integrity of character. He 'never found time' to marry. See Lives by Angus Smith (1836); Henry (1854); Lonsdale (1874); and Sir H. Roscoe (1895); and the article ATOMIC THEORY.