William Nicholson (December 13, 1753 - May 21, 1815) was an English polymath; chemist, natural philosopher, translator, journalist, publisher, inventor, patent agent and civil engineer. Anthony Carlisle (February 15, 1768 - November 2, 1840) was an English surgeon. On May 2, 1800 Nicholson and Carlisle discovered electrolysis by passing a voltaic current (direct electric current) through water, decomposing it into its constituent elements of hydrogen and oxygen (producing chemical reactions at the electrodes and separation of materials). The two were then appointed to a chemical investigation committee of the new Royal Institution. This image has been colorized.