(b. Feb. 18, 1745, Como, Lombardy [now in Italy]—d. March 5, 1827, Como)
Alessandro Giuseppe Antonio Anastasio Volta (also known as Count Volta) was an Italian physicist whose invention of the electric battery provided the first source of continuous current.
In 1775 Volta’s interest in electricity led him to invent the electrophorus, a device used to generate static electricity. He became professor of physics at the Royal School of Como in 1774 and discovered and isolated methane gas in 1778. One year later he was appointed to the chair of physics at the University of Pavia.
In 1780 Volta’s friend Luigi Galvani discovered that contact of two different metals with the muscle of a frog resulted in the generation of an electric current. Volta had been studying how electricity stimulates the senses of touch, taste, and sight. When Volta put a metal coin on top of his tongue and another coin of a different metal under his tongue and connected their surfaces with a wire, the coins tasted salty. Like Galvani, Volta assumed that he was working with animal electricity until 1796 when he discovered that he could also produce a current when he substituted a piece of cardboard soaked in brine for his tongue. Volta correctly conjectured that the effect was caused by the contact between metal and a moist body. Around 1800 he constructed what is now known as a voltaic pile consisting of layers of silver, moist cardboard, and zinc, repeated in that order, beginning and ending with a different metal. When he joined the silver and the zinc with a wire, electricity flowed continuously through the wire. This rudimentary form of battery produced a smaller voltage than the Leyden jar, an earlier device for storing static electricity, but it was easier to use because it could supply a steady current and did not have to be recharged.
In 1801 in Paris, Volta gave a demonstration of his battery’s generation of electric current before Napoleon, who made Volta a count and senator of the kingdom of Lombardy. The emperor of Austria made him director of the philosophical faculty at the University of Padua in 1815. The volt, a unit of the electromotive force that drives current, was named in his honour in 1881.