Cumming, James

Cumming, James

(b. London, England, 24 October 1777; d. North Runcton, Norfolk, 10 November 1861)

physics.

Cumming entered Trinity College, Cambridge, in 1797, graduated tenth wrangler in 1801, became a fellow in 1803, and was elected professor of chemistry in 1815, a position he held until the year before his death. He was apparently excellent as a teacher. Cumming’s scientific accomplishments, however, were limited—reportedly by ill health and lack of ambition—to a ten-year period early in his career: his published works span the years 1822–1833.

He became fascinated by the developments in electromagnetism following Oersted’s experiments and independently invented the galvanometer, describing it in greater detail than either Schweigger or Poggendorff. P. G. Tait gave Cumming credit for the independent discovery of thermoelectricity, but there seems to be no good reason to accept this. A brief announcement of Thomas Johann Seebeck’s discovery appeared in the Annals of Philosophy in 1822; Cumming’s first description was in the same journal in the following year. On the other hand, Seebeck’s detailed paper was not available until 1825. By then Cumming had compared the thermoelectric order of metals with the voltaic and conductivity series, noting the lack of any apparent connection. He also recorded the inversion effect which occurs with certain couples at high temperatures (Seebeck had remarked on this, as had A. C. Becquerel); this anomalous behavior was finally explained by William Thomson on the basis of thermodynamic arguments and the assumption of the “Thomson effect.” (Thomson had his attention drawn to this phenomenon by Becquerel’s paper but later recognized Cumming’s priority; he apparently never realized that it had been described in Seebeck’s original publication.)

Cumming was active in the founding of the Cambridge Philosophical Society and from 1824 to 1826 acted as its fourth president.

BIBLIOGRAPHY

I Original Works. The galvanometer is described in “on the Connexion of Galvanism and Magnetism,” in Cambridge Philosophical Society, Transactions, 1 (1821–1822), 268–279, and in “On the Application of Magnetism as a Measure of Electricity,” ibid., 281–286. The more important thermoelectric articles are “On the Development of Electromagnetism by Heat,” in Annals of Philosophy, 21 (1823), 427–429, and “A List of Substances Arranged According to Their Thermoelectric Relations, with a Description of Instruments for Exhibiting Rotation by Thermoelectricity,” ibid., 22 (1823), 177–180. The inversion effect was reported in “On Some Anomalous Appearances Occurring in the Thermoelectric Series,” ibid., 22 (1823), 321–323.

II. Secondary Literature. A biographical sketch appears in the Dictionary of National Biography. Reference is made there to some collected papers, but this author has been unable to discover any knowledge of their existence. The galvanometer is discussed in Robert A. Chipman, “The Earliest Electromagnetic Instruments,” in United States National Museum Bulletin, 240 (1964), 121–136.

Bernard S. Finn