Not Galvani's biggest fan. Image courtesy of Flickr user Velo Steve.
In the late 1780s visitors passing through the garden of the respected Bolognese doctor Luigi Galvani might have received a shock. He had draped dismembered frogs over his trellises in the name of scientific research.
Galvani believed that all living things contained an inherent electricity, what he called an animal electricity. His original evidence? Touching the exposed crural nerve in a (recently) dead frog’s leg with a metal scalpel caused the frog to kick out. A series of experiments followed, including one where Galvani stuck bronze hooks into the spinal columns of his frogs and hung their bodies over those garden trellises. When the bronze pressed against the iron bars, the frogs’ muscles contracted. By 1791 Galvani’s frog experiments had convinced him of the reality of animal electricity.
At first physics professor Alessandro Volta agreed with Galvani, but then came up with his own theory—one that relied on the contact of different metals. The frog was irrelevant and merely completed the circuit. Thus began a series of experiments and counter experiments in which each man provided further evidence for his theory.
Volta invented the battery as his final proof against a purely biological cause for electricity. Napoleon Bonaparte, impressed by this invention, made Volta a Count and a Senator of the Realm of Lombardy. The battery soon moved beyond his control as others began experimenting with its powers and properties. In 1800 two Englishmen followed Volta’s instructions for battery making and noticed a gas evolving from the water, bringing the battery into the realm of chemical processes. (Volta believed only physics was involved.) William Cruikshank used battery-powered chemistry to develop electroplating. And Humphry Davy used a giant battery to produce—for the first time—the elements potassium and sodium.
Galvani’s nephew, Giovanni Aldini, took animal electricity in a different direction, one later reflected in Mary Shelley’s Frankenstein (1818). He traveled throughout Europe giving demonstrations using animal and sometimes human bodies. His experiments led him to believe that he could restore life to those recently drowned. In 1804, he merged his uncle and Volta’s work when he used a battery to make the leg muscles of a dead man spasm—it appeared the body was about to get up and walk.
Perhaps the most striking demonstration was one performed by another man on a hanged murderer. Passing a current through a nerve on the forehead made expressions of rage, horror, despair, and happiness flit across the dead man’s face. Of the hardy medical men watching, one fainted and others had to leave the room. That this was their reaction is hardly, to me at least, a shock.
Michal Meyer is editor-in-chief of Chemical Heritage.
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