Electric Current

  Italian scientist Luigi Galvani was working in his Bologna laboratory in the 18th century when he accidentally touched a steel scalped to a frog's leg that was lying on a zinc plate.

The led twitched and Galvani believed he had discovered 'animal discovery'. In following up Galvani's research, his countryman Count Alessandro Volta, showed that it was the two metals that were responsible for generating the electric current and established the principle of the battery.