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The Voltaic Pile

A voltaic pile used in an early experiment. L. Galvani. Abhandlung über die Kräfte der thierischen Elektrizität auf die Bewegung der Muskeln, 1793

The voltaic pile, invented by Alessandro Volta in 1800, was the first electric battery. Its invention can be traced back to an argument between Volta and Luigi Galvani, Volta’s fellow Italian scientist who had gained notoriety for his experiments on frog legs.

An early voltaic pile

An early voltaic pile. A. Volta. On the electricity excited by the mere contact of conducting substances of different kinds, 1800

Galvani found that the legs of a frog would contract when forming a circuit with two different kinds of metal. Galvani contended that this phenomenon resulted from an inherent “animal electricity,” an electrical fluid present in the animal itself. Volta disagreed. His own experiments proved that this electric stimulation was ultimately the result of the different metals in the circuit and the electrolyte – that is, the frog legs – between them.

A later voltaic pile. L. Ferrari. Gli impianti domestici di luce elettrica, 1893

Removing this experiment from the theater of twitching legs, Volta created a circuit with two different metals separated by a piece of cloth or cardboard soaked in brine (an electrolyte). The completed circuit produced an electric current. By stacking this element – a pair of copper and zinc discs with an electrolyte between them – one atop the other, Volta could adjust the amount of electricity produced to his desired level. The result was what came to be called the voltaic pile, one of the first devices to provide a reliable source of electricity.

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