Page:Dictionary of National Biography volume 13.djvu/303

 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’ (, ‘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.



CUMMING, JOHN (1807–1881), divine, was born in the parish of Fintray, Aberdeenshire, 10 Nov. 1807. He was educated at the Aberdeen grammar school, and in 1822 became a student at the university. He showed ‘brilliant promise,’ and graduated M.A. in 1827. He then studied in the Divinity Hall, and during vacations acted as a private tutor. He was licensed to preach 3 May 1832 by the Aberdeen presbytery. Soon afterwards, while acting as tutor in Kensington, he was invited to preach in the National Scottish Church at Crown Court, Covent Garden. On 18 Aug. 1832 he received a call from the church. In 1833 he married Elizabeth, daughter of James Nicholson, one of the elders. The church was then very small and inconvenient, and the minister's income not over 200l. His preaching soon attracted a larger congregation; and in 1847 the church was rebuilt at a cost of 5,000l. It was opened in 1848, with sittings for a thousand persons. The income from pew rents reached 1,500l.; but Cumming refused to receive more than 900l., the remainder paying off the debt incurred for rebuilding. He afterwards raised funds by which schools in Little Russell Street were added in 1849; and ragged schools, with a church, in Brewer's Court in 1855. Cumming took an active part in a great number of philanthropic movements, and was a popular preacher. Cumming was prominent as a controversialist. He opposed the seceders, who ultimately formed the Free church, in many pamphlets and lectures. He declined several invitations to accept important charges in Scotland, vacated through that event. In 1839 he had a public discussion at Hammersmith, in which he defended protestant doctrine against Daniel French, a Roman catholic barrister. The published report went through many editions. He took part in the Maynooth controversy of 1845; he lectured on the same subject for the Protestant Reformation Society in 1849; he presided at meetings to protest against the ‘papal aggression’ of 1850; and had a correspondence with Cardinal Wiseman upon the ‘persecuting clause’ of the archiepiscopal oath. A testimonial was presented to him, to which the Duke of Norfolk subscribed. In 1853 the Wiseman controversy was revived, and a meeting was held at Exeter Hall, which the cardinal was invited to attend. Cumming became most widely known by his writings on the interpretations of prophecy, holding that the ‘last vial’ of the Apocalypse was to be poured out from 1848 to 1867. In 1863 he lectured against Bishop Colenso. In 1868, when the Œcumenical Council was summoned by Pius IX, Cum-