Luigi Galvani's Animal Electricity

Online exhibition looking at how electricity in a medical capacity has developed from the Antiquities through to the early twentieth century. Quack treatments are examined alongside studies of anatomy and x-rays.

Engraving from a very rare 1st edition of Galvani's De viribus electrictatis from 1791

The true nature of our relationship to electricity began to be revealed in 1771 when a chance observation led Luigi Galvani (1737-98) to discover animal electricity. Apparently, when the nerve of a frog that Galvani's wife was preparing for soup was accidentally touched with a knife a muscle contraction occurred despite the frog not being connected to an electrical machine. Galvani investigated the cause and discovered that contractions were excited when two different metals touched.

Previously, Isaac Newton had theorised a link between the 'animal spirits' described in antiquity and the subtle electrical fluid hypothesised by physicists. Caldini and Fontana had realised that merely bringing an electrified rod within their close proximity would stimulate frogs. However, it was Galvani who determined that electricity was present within the animal itself. Based on his frog experiments he deduced that contractions were caused by the flow of electricity and when one occurred a nervo-electric fluid was conducted from the nerves to the muscle.

Drawing by Michael Faraday of an electric fish

This discovery appeared to provide a definitive physiological basis for medical electrical treatment, however it was not without its critics, most notably the famous Italian physicist Alessandro Volta.

Next page → Volta vs Galvani in the animal debate

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