Davy, Sir Humphry, Baronet b. Dec. 17, 1778, Penzance, Cornwall, Eng. d. May 29, 1829, Geneva English chemist who discovered several chemical elements (including sodium and potassium) and compounds, and became one of the greatest exponents of the scientific method. Davy is best remembered for his contributions to the understanding of electrochemistry and for his invention of a safety lamp for ...