The English chemist and natural philosopher Sir Humphry Davy (1778-1829) isolated and named the elements of the alkaline-earth and alkali metals and showed that chlorine and iodine were elements.

Humphry Davy was born on Dec. 17, 1778, in Penzance, Cornwall. He was apprenticed when he was 16 to an apothecary in Penzance, where he evinced a great interest in chemistry and experimentation, using as his guide Lavoisier's famous work, Traité élémentaire de chimie. His obvious talents attracted the attention of Gregory Watt and Davies Giddy (later Gilbert), both of whom recommended him to Dr. Thomas Beddoes for the position of superintendent of the newly founded Pneumatic Institution in Bristol. He worked there from October 1799 to March 1801.

The Pneumatic Institution was investigating the idea that certain diseases might be cured by the inhalation of gases. Davy, sometimes perilously, inhaled many gases and found that the respiration of nitrous oxide produced surprising results. Inhalation of "laughing gas," as it was soon called, became a novel form of entertainment, although nearly 50 years passed before it was actually used as an anesthetic. Davy also experimented with the newly invented voltaic pile, or battery.

Davy left Bristol to become the lecturer in chemistry at the Royal Institution in London. Sir Joseph Banks and Count Rumford had founded the Royal Institution in 1799 as a research institute and as a place for educating young men in science and mechanics. Here Davy's genius emerged full-blown. Not only did his brilliant lectures attract a fashionable and intellectual audience, but he also continued his electrical research. In 1806 he showed that there was a real connection between electrical and chemical behavior; for this achievement Napoleon I awarded him a prize. In 1807 he electrolyzed molten potash and soda and announced the isolation of two new elements, naming them potassium and sodium. In 1808 he isolated and named calcium, barium, strontium, and magnesium. Later he showed that boron, aluminum, beryllium, and fluorine existed, although he was not able to isolate them.

Lavoisier had claimed that a substance was an acid because it contained oxygen. Davy doubted the validity of this claim and in 1810 showed that "oxymuriatic acid gas" was not the oxide of an unknown element, murium, but a true element, which he named chlorine.

In 1812 Davy married a wealthy widow, Jane Apreece, and was knighted by the King for his great discoveries. Napoleon I invited him to visit France, even though the two countries were at war. Sir Humphry and his wife went to France in 1813, taking with them as valet and chemical assistant the 22-year-old Michael Faraday. The French presented them with a curious substance isolated from seaweed, and Davy, working in his hotel room, was able to show that this was another new element, iodine. When he returned to England, he was asked by a group of clergymen to study the problem of providing illumination in coal mines without exploding the methane there. Davy devised the miner's safety lamp and gave the invention to the world without attempting to patent or otherwise exploit it. Working in another area, he demonstrated how electrochemical corrosion could be prevented.

In 1820, after Sir Joseph Banks had died, Sir Humphry was made president of the Royal Society. He began the needed internal reform of the society, but bad health forced him to resign in 1827. The remaining years of his life he spent wandering about the Continent in search of a cure for the strokes from which he suffered. He died on May 29, 1829, in Geneva, Switzerland, where he was buried.

Further Reading

• Davy's own writings are the best source of information about his scientific work. They were edited in nine volumes by his brother, John Davy, The Collected Works of Sir Humphry Davy (1839-1840). A complete listing of all his writings is in June Z. Fullmer, Sir Humphry Davy's Published Works (1969). John Davy wrote a biography, Memoirs of the Life of Sir Humphry Davy (2 vols., 1839), to correct the excesses of John Ayrton Paris's biography, The Life of Sir Humphry Davy (2 vols., 1831). Recent biographies are Anne Treneer, The Mercurial Chemist: A Life of Sir Humphry Davy (1963), which discusses Davy's relationship to the romantic poets, and Sir Harold Hartley, Humphry Davy (1966), which concentrates on his life and importance as a scientist.