Coloured engraving of the Italian physicist Alessandro Volta (1745-1827). He became interested in electricity in 1786 following on the work of Galvani.He was the first to show that an electrical current flowed when two dissimilar metals were brought into contact.Volta invented the electric battery in 1800 and announced his discovery in a letter to the Royal Society. His first battery (pile) consisted of alternating disks of silver and zinc with brine-soaked card between them. This produced a steady electric current and was the first reliable source of electricity. He drew up a list of metals according to their propensity to generate electricity when stimulated. This is known as the electrochemical series. The battery shown on his left used zinc and copper discs.The unit of electrical potential, the volt (V), is named after him.