Cumming, James (1777-1861) (DNB00)

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CUMMING, JAMES (1777–1861), professor of chemistry at Cambridge, was descended from the Scotch family of Cumming of Altyre. His grandfather, however, left Scotland after Culloden, and James Cumming was born in England on 24 Oct. 1777. Entering Trinity College, Cambridge, in 1797, he graduated tenth wrangler in 1801, and became fellow in 1803. He was proctor in 1818. While a student he made many experiments in natural philosophy, and in 1815 he was elected professor of chemistry in succession to Smithson Tennant [q. v.] He was keenly alive to the chemical and physical discoveries being rapidly made at that time, and in 1819 he gave in his lectures Oersted's famous experiments, showing the deviation produced in a magnetised needle by an electric current parallel to its axis, and observed, ‘Here we have the principle of an electric telegraph.’ He was one of those who contributed much to the early fame of the Cambridge Philosophical Society, of which he was for some time president, and his papers in its ‘Transactions,’ vols. i. and ii., and in Thomson's ‘Annals of Philosophy,’ new ser. vols. v. vi. and vii. (1823–4), though extremely unpretentious, are landmarks in electro-magnetism and thermo-electricity. He ‘seems, in fact, to have made an independent discovery of thermo-electricity’ (Tait, ‘Rede Lecture,’ Nature, 29 May 1873, p. 86). He constructed most delicate electroscopes, and made important modifications and simplifications of electrical methods. He was the first to show, in 1823, that when the temperature of one junction of certain thermo-electric circuits was gradually raised, the current gradually rose to a maximum, then fell off, and finally was reversed at a red heat. He published an extended thermo-electric series in an appendix to his important paper ‘On the Development of Electro-Magnetism by Heat’ (Camb. Phil. Trans. ii. 47–76), read 28 April 1823. Had he been more ambitious and of less uncertain health, his clearness and grasp and his great aptitude for research might have carried him into the front rank of discoverers. He was remarkable for getting at the pith of any question and presenting it clearly, and thus made an excellent teacher, to which result also the success of his experiments contributed. He continued to lecture till 1860, and for years after went on working in his laboratory, within a few weeks of his death suggesting some ingenious crucial experiments in physical optics. He died on 10 Nov. 1861 at North Runcton, near Lynn, Norfolk, of which place he had been rector since 1819. Cumming was highly respected for his independence of thought and action and his kindly and unostentatious character. He was a liberal, well read in literature, conversationally polished, and good-naturedly ironical.

In 1827 Cumming published ‘A Manual of Electro-Dynamics,’ based on Montferrand's ‘Manuel d'Electricité Dynamique,’ with large additions and improvements. His papers, besides those already referred to, include a ‘Report on Thermo-Electricity’ in ‘Brit. Assoc. Reports,’ 1831–2, and two other papers, ib. 1833.

[Cambridge Independent Press, 16 Nov. 1861; Cumming's papers; Tait, loc. cit.]

G. T. B.