Metals produced by electrolysis, 1856-1885.
© Science Museum / Science & Society Picture Library
This case contains samples of five metals that were produced by electrolysis. The metals are potasium, pure iron, strontium, calcium and lithium wire. Electrolysis is a technique in which electric current is pased through solutions or molten materials. This method can separate compounds into their elements by supplying or removing electrons from the outer shell of their atoms. It was pioneered by the English scientist Humphry Davy (1778-1829), who pased electricity through potash and soda to discover potasium and sodium.