The taming of the ray and a “paradigmatic” torpedo: Electric fish research between the 17th and 18th century

Università di Ferrara, Italy

Few episodes illustrate the transition from the opinions of ancient epochs to modern science better than the demonstration of the electric nature of the shock given by some singular fish, such as torpedo, the eel of Guiana, and Nile catfish. The crucial episode in this transition is due to the endeavour of the English “natural philosopher” John Walsh. After about two intense weeks of experiments on torpedoes carried out at La Rochelle in France, Walsh was able to write in his laboratory notebook (in an approximate French): “Je l’ai donté,” I have tamed “the indomitable virtue of the wonderful torpedo,” thus expressing his pride in achieving the evidence of the electric nature of this “virtue.” About one century before Walsh, in the wave of the Galilean scientific revolution, the shock of the torpedo had been the object of an intense investigation which led to the conclusion of its mechanical nature. This was due particularly to the work of Stefano Lorenzini (the Lorenzini of the ampullar electroreceptors). However, Walsh (and, after him, Lazzaro Spallanzani) denied the presence and importance of any mechanical phenomenon in the torpedo’s shock, their observations thus standing in remarkable contrast with Lorenzini’s detailed description of the movement of fish organs (or “muscoli falcati”) during the shock. Besides, on the basis of a Kuhnian paradigm shift, the difference between the mechanical and electrical views can be explained by taking into account a simple and somewhat surprising observation: in the case of Lorenzini’s experiments torpedo really moved but the movement was more the effect than the cause of the shock.

Session II
Tuesday, 5 July 2005, 11.30 am - 12.00 pm

Tenth Annual Meeting of the International Society for the History of the Neurosciences (ISHN) and
Tenth Meeting of the European Club for the History of Neurology (ECHN)

St. Andrews, Scotland, 2005