252 Tlic late Dr. Thomas Thomson. 



the University of Edinburgh, at that time taught by Dr. Black— a man 

 of whom he could never speak without admiration. Although all Dr. 

 Black's discoveries were made before 1766, when he left the chair of 

 chemistry in Glasgow, the lectures he continued to give in Edinburgh were 

 scarcely less remarkable, and were no doubt of immense advantage to 

 Thomson. As published after his death by his friend Professor Eobison, 

 they contain an inexhaustible fund of information, and are wonderfully 

 free of the errors of the time. During the session of his attendance at 

 Dr. Black's lectures, Dr. Thomson wrote the article on the " Sea," for 

 the Encyclopaedia Britannica. In November 1796 he succeeded his 

 brother in the editorship of the Supplement to the third edition of that 

 work, and remained in this position till 1800. It was during this period 

 that he drew up the first outline of his System of Chemistry, which 

 appeared in the Supplement under the articles, " cliemistry, mineralogy, 

 vegetable substances, animal substances, dyeing substances." These all 

 appeared before the year 1800, when the preface was published which 

 contains the following remarks by Dr. Gleig. " Of the writer," he says, 

 "of these beautiful articles, a man of like principles with Dr. Robison, it 

 is needless to say anything, since the piiblic seems to be fully satisfied 

 that they prove their author eminently qualified to teach the science of 

 chemistry." From this passage it may be inferred that it was during the 

 winter of 1800-01, that Dr. Thomson first gave a course of lectures on 

 chemistry. He was thus before the public as a lecturer for the long 

 period of fifty-two years, and for some time before his death he had 

 considered himself the oldest teacher in Europe. He graduated in 1799. 

 "The self-taught chemist," says Dr. R. D. Thomson, "began to devise 

 many of his views in a narrow close in the High-Street of Edinburgh; 

 the author being in the receipt of a salary of £50 a-year, from which he 

 sent £1.5 to his aged parents." 



Dr. Thomson continued to lecture in Edinburgh till 1811, and during 

 that time he opened a laboratory for pupils, probably the first establishe'd 

 in Great Britain. Among those who worked there, was Dr. Henry of 

 Manchester, who had visited Edinburgh for the purpose of graduation, 

 and who there made his first experiments on the constituents of coal gas. 

 During this period, Dr. Thomson likewise made investigations for 

 government on the malt and distillation questions, and afterwards wrote 

 the article " Distillation" in the Edinburgh Encyclopajdia. He also 

 invented his Saccbarometer, still used, according to Dr. R. D. Thomson, 

 by the Scottish excise, under the tide of Allan's Saccharometcr. 



In 1812 Dr. Thomson published his history of the Royal Society, 

 which might rather be called a Digest of the " Philosophical Transac- 

 tions." The papers are arranged in it under distinct heads, according to 

 the sciences to which they respectively belong. Every science is intro- 

 duced by a history commencing with its origin, and traced down to the 

 period of the establishment of the Royal Society. Sketches are also 

 given of the lives of the most eminent of the contributors. 



