Faraday's electrolysis globe, 1834.
© Science Museum / Science & Society Picture Library
Reconstruction made in 1931. The original object is part of the Royal Institution Collection. During electrolysis, electric current was pased through this voltameter to cause chemical reactions. It was used by Michael Faraday (1791-1867) to study the decomposition of water by electricity. Hydrogen came off at one electrode and oxygen at the other. Faraday was one of the greatest of all experimental physicists.