(1778–1829)
an English chemist who was one of the first scientists to make use of electricity to break chemical compounds into their separate elements. Between 1807 and 1808 he discovered six chemical elements, including calcium, potassium and sodium. However, he is better known for a practical invention that saved many lives: the Davy lamp , a safe lamp for use in coal mines. This was widely used in mines until it was replaced by the electric lamp in the 20th century.