# Dictionary of National Biography, 1885-1900/Thomson, Thomas (1817-1878)

​THOMSON, THOMAS (1817–1878), naturalist, born in Glasgow on 4 Dec. 1817, was eldest son of Thomas Thomson (1773–1852) [q. v.], professor of chemistry in the university of Glasgow, by his wife Agnes Colquhon, daughter of a distiller near Stirling. Thomas was educated at the high school and the university of Glasgow. Throughout his college career he specially devoted himself to science, and when only seventeen discovered and described the celebrated beds of fossil mollusca on the Firth of Clyde, drawing conclusions that showed remarkable powers of generalisation.
Intending at first to adopt chemistry as a profession, he passed some years in the university laboratory, and spent a winter at Giessen under Liebig, when he discovered pectic acid in carrots. On entering the medical classes at Glasgow he concentrated ​his attention on botany, under Sir William Jackson Hooker [q. v.]
After graduating M.D. at Glasgow University in 1839 he entered the service of the East India Company as assistant surgeon, and on his arrival in Calcutta early in 1840 was appointed to the curatorship of the museum of the Asiatic Society. He had begun the arrangement of their collection of minerals when in August he was sent to Afghanistan in charge of a party of European recruits. He reached Cabul in June 1841, and proceeded to Ghuznee, where he was attached to the 27th native infantry. He was besieged in Ghuznee during the winter, and was made a prisoner when the place fell in March 1842. He was destined to be sold into slavery in Bokhara, but, with some fellow-prisoners, succeeded in bribing his captor to convey him to the British army of relief. Before he was closely beleaguered he had been employed in making a study of the geology and botany of the district. He returned to India without his collections and personal effects, and was stationed with his regiment at Moradabad till 1845, when he joined the army of the Indus and served through the Sutlej campaign, after which he returned to Moradabad and was stationed at Lahore and Ferozepur. During this period he was engaged in investigating the botany of the plains and outer Himalayas. In August 1847 he was appointed one of the commissioners for defining the boundary between Kashmir and Chinese Thibet, and reached Léh in October. He made extensive journeys in the Kashmir territories, going as far north as the Karakoran Pass, and obtaining most important geographical information, besides valuable collections. After his return to India he took furlough at Simla, where he finished his report and made further botanical researches.
At the end of 1849 he joined his friend Dr. (now Sir Joseph Dalton) Hooker in Darjeeling, and, in lieu of going to England, spent 1850 in travelling with him in the Sikkim forests, the Khasi hills, Cachar, Chittagong, and the Sunderbunds, finally returning to England in very broken health in March 1851. The next few years were spent at Kew, working at the collections obtained during these travels. In the mistaken belief that assistance would be given by the company, he brought out, in conjunction with Hooker, at his own expense, and issued at cost price, the first volume of a work entitled ‘Flora Indica,’ London, 1855, 8vo; but the sole support he obtained from the company was the offer to purchase some copies.
In 1854 Thomson succeeded Dr. Falconer as superintendent of the botanical garden at Calcutta. He was also appointed professor of botany at the Calcutta medical college, and held the two posts till 1861, when he retired and returned to England in ill health. He resided first at Kew and then at Maidstone. In 1871 he went again to India as secretary to the expedition fitted out to observe the eclipse of the sun on 12 Dec. of that year. He died on 18 April 1878. He married, in 1854, Catharine, daughter of R. C. Sconce, esq., of Malta.
Thomson was elected a fellow of the Linnean Society in 1852, of the Royal Geographical Society in 1854, and of the Royal Society in 1855. He was for twelve years an examiner in natural science for the medical services of the army and navy, and on several occasions examiner in botany for the university of London and the South Kensington school of science.
Besides the work already named, and official reports as superintendent of the Calcutta botanic garden, Thomson was author of:
* ‘Western Himalaya and Tibet,’ London, 1852, 8vo.
* ‘Note on Captain Grant's Collection of Plants’ in Speke's ‘Journal of the Discovery of the Source of the Nile’ (appendix), 1863. He also wrote eleven papers on geographical and botanical subjects, as well as nine botanical papers with Sir J. D. Hooker for various scientific journals between 1835 and 1867.
A crayon portrait by Richmond, dated 1854, is at Kew.
[Proc. Royal Geographical Society, xxii. 309; Journ. Bot. 1878, p. 160; information kindly supplied by J. G. Baker, esq., F.R.S.]
B. B. W.