I wish to thank Dr. Robert P. Multhauf, chairman of the Department of Science and Technology in the Smithsonian Institution's Museum of History and Technology, for encouragement in the writing of this paper and for the provision of opportunity to consult the appropriate sources. To Dr. W. James King of the American Institute of Physics, I am grateful for many provocative discussions on this and related topics.
[1] A. VOLTA, "On the Electricity Excited by the Mere Contact of Conducting Substances of Different Kinds," _Philosophical Transactions of the Royal Society of London_ (1800), vol. 90, pp. 403-431.
[2] Some little-known but delightful observations in the prehistory of electromagnetism are described in a letter written by G. W. SCHILLING from London to the Berlin Academy on July 8, 1769, published as "Sur les phénomènes de l'Anguleil Tremblante" [_Nouveaux Mémoires de l'Académie Royale des Sciences et Belles-Lettres_, 1770 (Berlin, 1772), pp. 68-74], translated to French from the original German. The letter recounts a multitude of experiments with various electric eels. The two observations of electromagnetic interest are that a piece of iron held by the hand in the eel's tank could be felt quivering even when the fish was stationary several inches away, and a compass needle showed a deflection, both in the water near the fish, and outside the tank, also with the fish stationary.
[3] ABRAHAM BENNET, _Philosophical Transactions of the Royal Society of London_ (1787), p. 26.
[5] _Philosophical Magazine_ (1800), vol. 7, pp. 289-311. [For a facsimile reprint, see _Galvani-Volta_ (Bern Dibner's Burndy Library Publication No. 7), Norwalk, Connecticut, 1952.]
[6] MICHAEL FARADAY, _Experimental Researches in Electricity_, vol. 1 (London, 1839), paragraph 739, dated January 1834.
[8] JAMES CUMMING, "On the Application of Magnetism as a Measure of Electricity," _Transactions of the Cambridge Philosophical Society_ (1821), vol. 1, pp. 282-286. [Also published in _Philosophical Magazine_ (1822), vol. 60, pp. 253-257.]
[9] H. C. OERSTED, _Experimenta Circa Effectum Conflictus Electrici in Acum Magneticam_ (Copenhagen, July 21, 1820).
[10] Full details of Oersted's work and publications are in _Oersted and the Discovery of Electromagnetism_ (Bern Dibner's Burndy Library Publication No. 18), Norwalk, Connecticut, 1961. The original Latin version and first English translation are reproduced in _Isis_ (1928), vol. 34, pp. 435-444.