THOMSON, Thomas, an eminent chemist, was born at Crieff in Perthshire, on the 12th of April 1773. Passing from the parish school of his native town, he became a pupil of Dr Doig of Stirling, and subsequently entered the University of St Andrews. After spending three years at this seat of learning, he entered upon his medical studies at the University of Edinburgh, and in 1796 became connected with the Encyclopædia Britannica, for an early edition of which he wrote the articles CHEMISTRY, MINERALOGY, VEGETABLE SUBSTANCES, ANIMAL SUBSTANCES, DYEING SUBSTANCES, &c. These articles formed the basis of his System of Chemistry, which he published at Edinburgh in 1804, in 4 vols., and afterwards greatly enlarged and improved as the demand for the book increased. Dr Thomson's lectures on chemistry, which he commenced at Edinburgh in 1800, were continued with increasing popularity until 1810. Meanwhile he invented the system of chemical symbols, which are now substantially adopted by men of science; and he was the first to open a laboratory in Britain for practical manipulation. He published his Elements of Chemistry in 1810. In 1812 he visited Sweden, and wrote a description of that country on his return. Dr Thomson commenced the Annals of Philosophy in 1813, and was chosen lecturer on chemistry to the University of Glasgow in 1817, which was elevated into a professorship the year following. He was one of the first
to recognise the value of Dalton's atomic theory. The works of this eminent chemist were henceforward numerous and popular. He wrote, in 1825, in 2 vols., An Attempt to Establish the First Principles of Chemistry by Experiment; in 1830-31, he published the History of Chemistry in 2 vols.; in 1836, appeared likewise in 2 volumes, his Outlines of Mineralogy and Geology; and in 1849 he issued his last work, on Brewing and Distillation. Thomson made a great many discoveries in chemistry, and has left behind a considerable reputation both as an original discoverer and as a practical teacher of his favourite science. Dr Thomas Thomson died in 1852. His son, who bears his name, is known to be a distinguished botanist, and is superintendent of the East India Company's Botanic Gardens at Calcutta.