Davy, Sir Humphry (1778-1829), a British chemist. Davy discovered the elements potassium and sodium (1807), and barium and calcium (1808). These discoveries resulted from his researches in electrochemistry. He was the first to isolate magnesium and strontium (1808). He also isolated boron (1808) independently of the French chemists Gay-Lussac and Thnard. His miner's safety lamp (1815) was a major contribution to industrial safety. Although two other men claimed this invention, Davy is generally given the credit.

Davy was born in Cornwall. As an apprentice to an apothecary and surgeon, he became interested in chemistry. In 1799 as an assistant in the Pneumatic Institution of Bristol, he made important discoveries about the properties of nitrous oxide. This accomplishment won him an appointment, at 23, as professor of chemistry at the Royal Institution of Great Britain, London.

Davy's talent for storytelling, combined with his brilliant scientific record, made him one of the most popular lecturers of his day. Although Britain and France were enemies at the time, Davy was awarded the Napoleon Prize of the French Institute in 1808. He was knighted in 1812 and was made a baronet in 1818. He became president of the Royal Society in 1820.