Edward Bancroft and the "torporific" eels of Surinam
Edward Bancroft (1744-1821) is often remembered for two things: (1) for acting as secretary to Franklin and the American commissioners in France during the War for Independence, and (2) because being a double agent, spying for the British on the Americans and the Americans on the British.
Prior to becoming a spy, Bancroft studied medicine in Connecticut. Before completing his medical apprenticeship, he ran off to Dutch Guiana (Surinam), where he worked as a medical assistant and collected material for a book on the area, including its flora and fauna. He remained in Surinam from 1763 to 1766 and then settled in London, where he published his descriptive book in 1769, after more medical training under Pitcairn at St. Bartholomews.
One of the sections in An Essay on the Natural History of Guiana was on the river eels, which had been briefly described by La Condamine and by a few of the Dutch who had been in the area. Yet the eel was still not well known in Europe when Bancroft vividly wrote about its powerful shocks and gave reasons to believe that they must be electrical, not mechanical.
During the 1770s, John Walsh confirmed Bancroft's ideas, putting to rest the idea that shocks from electric fish are mechanical. Walsh, like Bancroft, was a member of the Royal Society, where Benjamin Franklin actively encouraged others to conduct experiments on electricity (both from machines and the heavens), and, in Walsh's case, on forces seemingly electrical (i.e., from certain fish). The work of Bancroft, Walsh, and others in Franklin's circle led to a new neurophysiology by showing that animals could, in fact, produce electricity. Franklin would never learn that the New Englander who had piqued his interest in animal electricity was already being paid to spy on his activities.
Session II. Natural History
12th Annual Meeting of the International Society for the
History of the Neurosciences (ISHN)