The concept of the fuel cell was first demonstrated by Humphry Davy in 1801, but the invention of the first working fuel cell is credited to William Grove, a chemist, lawyer, and physicist. Grove's experiments with what he called a "gas voltaic battery" proved in 1842 that an electric current could be produced by an electrochemical reaction between hydrogen and oxygen over a platinum catalyst. English engineer Francis Thomas Bacon expanded on Grove's work, creating and demonstrating various Alkaline fuel cells from 1939 to 1959.