Sir Humphry Davy, 1st Baronet (17 December 1778 – 29 May 1829) was a British chemist and inventor who invented the Davy lamp and a very early form of arc lamp. He is also remembered for isolating, by using electricity, several elements for the first time: potassium and sodium in 1807 and calcium, strontium, barium, magnesium and boron the following year, as well as for discovering the elemental nature of chlorine and iodine. Davy also studied the forces involved in these separations, inventing the new field of electrochemistry. He is credited with discovering clathrate hydrates.
In 1799, he experimented with nitrous oxide and was astonished at how it made him laugh. He nicknamed it "laughing gas" and wrote about its potential as an anaesthetic to relieve pain during surgery.