"[Humphry Davy] early began to experiment on , and soon succeeded in developing the fundamental laws of electro-chemistry; and in 1807 he effected the decomposition of [[w:Potassium hydroxide|[caustic] potash]] and [[w:Sodium hydroxide|[caustic] soda]] by the application of voltaic electricity thereby establishing... that the alkalis are compound substances. He subsequently proved that this was also the case with the alkaline earths. Davy thus added some five or six metallic elements to those already known."