The Experiments of Ramón M. Termeyer SJ on the Electric Eel in the River Plate Region (c. 1760) and other Early Accounts of Electrophorus electricus

Abstract

This paper focuses on Ramón M. Termeyer SJ (1737–1814?), a naturalist who experimented with the electric eel in the River Plate region during the 1760s. After going through an enumeration of the chroniclers that since the sixteenth century noticed the benumbing discharge of Electrophorus electricus, the article summarizes the work that immediately preceded Termeyer's and considers as a term of comparison the experiments on the electric eel performed by Bertrand Bajon (fl. 1751–1778) in the French Guyanne. It ends by discussing the meaning of Termeyer's 1781 and 1810 articles in the light of contemporary ideas of animal electricity.

Keywords:

• animal electricity
• electric fish
• Ramón Termeyer
• Bertrand Bajon

Initial research for this paper was done at the Cambridge University Library while I was a Visiting Fellow at Clare Hall supported by Fundación Antorchas (Argentina). Further elaboration and the writing of the paper were supported by a grant of the John Simon Guggenheim Memorial Foundation during my tenure as Latin American Guggenheim Fellow 2006–2007. Dr. Esteban Bontempi (Karolinska Institutet) and Dr. Juan P. Garrahan (University of Nottingham) were kind enough to help me with two bibliographical items. Dr. Pablo Schwarzbaum (University of Buenos Aires) and Drs. Leandro Tamini, Ricardo Ferriz, and Francisco Firpo (Museo Argentino de Ciencias Naturales) were extremely helpful with their discussion of the identification of Termeyer's “eel.” The final version of the paper was improved by the criticisms and editorial comments of the referees and editors. In particular I wish to thank Stanley Finger for calling my attention to a fuzzy reference.

Notes

¹ The electric “eel” is not really an eel but a fresh-water fish of the gymnotidae family. It was named Gymnotus electricus by Linnaeus and Electrophorus electricus after 1864. Eighteenth-century authors usually referred to it as “gymnotus.”

² A missionary who really did travel extensively through Africa during the heyday of Portuguese occupation of the continent, the Dominican João dos Santos, also mentions the Nile catfish in his Ethiopia Orientalis published in Évora in 1609 (Dos Santos, 1965, p. 227).

³ Adanson stumbled upon Malapterurus electricus during his travels through West Africa, the narrative of which was published as Histoire naturelle du Sénégal (Paris, Bauche, 1757) (Keynes, 1956, p. 215). In Leyden, from 1715 onwards, Willem 's Gravensande, Pieter van Musschenbroek, and other physicists had committed themselves to following a Newtonian program of research strictly grounded on experimentation (Goodman & Russell, 1991, pp. 261–264). Among its results, we can count the invention in 1745 by van Musschenbroek of the condenser aptly called “Leyden jar”—actually, the jar had been described by others, and several authors were simultaneously experimenting with it (Hoff, 1936, pp. 161–162). Termeyer mentions the letter written on November 22, 1754 by Storm van ‘s Gravesande, governor of Essequibo (1742–1750), as an answer to an inquiry of the physician J. N. S. Allamand, professor of natural philosophy at Leyden, in which the functionary argued that he had been unable to detect any spark accompanying the discharge, which he thought was of an electric nature (Allamand, 1758; cf. Walker, 1937, p. 89). He also refers to the letter sent from Essequibo on June 22, 1761 by Frans van der Lott, with an account of the supposedly therapeutic properties of the shocks delivered by the fish, which were used as a folk remedy (Van der Lott, 1762; cf. Kellaway, 1946, pp. 135–136). During the 1760s the Utrecht physician Schilling (see main text), who lived for 13 years in Surinam, also experimented with the effect of magnets on electric eels and reported that the fish was attracted by the magnet and as a result lost its ability of generating a shock (Schilling, 1772).

⁴ The greatest problem concerning the identification of Termeyer's fish is that the geographical range of Electrophorus electricus reaches no further south than the lower Amazon basin. The electric eel is not found in the Paraná River or any of its tributaries (Ringuelet, Aramburu, & Aramburu, 1967; Menni, 2004). Termeyer could not have meant any of the several species of gymnotiform fish, locally called “knife-fish,” which produce weak electric fields for electrolocation and communication (Trujillo-Cenóz, 1990). Electrophorus electricus is the only South American freshwater fish capable of delivering shocks of the magnitude recorded by Termeyer. The only way out of this problem is to accept that there was a change in the geographical distribution of the fish.

⁵ Termeyer could even have confused the “physiological light” elicited in Volta's experiments consisting of connecting the extremes of a bimetallic arc to the conjunctiva—or, alternately, one extreme of the arc to the conjunctiva and the other to the tongue— with the difficulty in obtaining a light (spark) from the eel (cf. Piccolino, 2000, pp. 149–150).

⁶ Termeyer wrote his first paper in 1781, the year in which Felice Fontana published in Florence his Traité sur le vénin de la vipère, in which he advocates the idea that muscular contraction should be explained by “common electricity” or something “very analogous to it.” Fontana affirmed that “the electrical gymnotus and torpedo, if they do not render the thing very probable, make it at least possible” (cited in Hoff, 1936, p. 168). It is not altogether unlikely that Fontana's work could have had some bearing on Termeyer's paper (although, as has been discussed, what probably prompted him to write his paper was the announcement that Walsh had been able to obtain a spark). Seen from the point of view of the electrical hypothesis of muscular contraction, Termeyer's 1781 paper was a witness to the turning of the tide in the opinion of physiologists, which signaled a transition from a concept of a nonelectric nervous fluid—more or less inspired in the theories of Albrecht von Haller—to the gradual acceptance of its electrical nature.

Piso W, Markgraf G (1648): Historia naturalis Brasiliae. Leyden, F. Hackius; Amsterdam, L. Elzevir.