- Davy , Sir Humphry
- (1778–1829) British chemistThe son of a small landowner and wood-carver, Davy went to school in his native town of Penzance and in Truro. At the age of 17 he was apprenticed to an apothecary and surgeon with a view to qualifying in medicine. He was self-reliant and inquisitive from an early age and taught himself chemistry from textbooks. In 1798 he was appointed to Thomas Beddoes's Pneumatic Institute at Clifton, Bristol, to investigate the medicinal properties of gases. Davy's first papers were published by Beddoes in 1799. In one he concluded, independently of Count Rumford, that heat was a form of motion; the other contained some fanciful speculations on oxygen, which he called phosoxygen. Davy soon discovered the inebriating effect of nitrous oxide and his paper Researches, Chemical and Philosophical; chiefly concerning Nitrous Oxide(1800), and the subsequent fashion for taking the ‘airs’, made him famous. At Clifton he met many eminent people, including the poets William Wordsworth, Samuel Taylor Coleridge, and Robert Southey (Davy was himself a Romantic poet), and his flirtation with fashionable society began.In 1801 Davy moved to London, to the Royal Institution, where his lectures were spectacularly successful. At Clifton he had begun to experiment in electrochemistry, following William Nicholson's electrolysis of water, and this was to prove his most fruitful field. In the early years at the Royal Institution, however, he did much work of an applied nature, for example on tanning and on agricultural chemistry. In his 1806 Bakerian Lecture to the Royal Society he predicted that electricity would be capable of resolving compounds into their elements and in the following year he was able to announce the isolation of potassium and sodium from potash and soda. This result cast doubts on Antoine Lavoisier's oxygen theory of acidity. Davy was essentially a speculative and manipulative chemist, not a theorist, and he reasoned incorrectly that ammonia (because of its alkaline properties), and hence nitrogen, might contain oxygen. He remained skeptical about the elementary nature of bodies for many years and tried to show that sulfur and phosphorus contained hydrogen.Davy's work in the years immediately following the discovery of sodium was hindered by his social success and competition for priority with the French chemists Joseph Gay-Lussac and Louis Thenard. He prepared boron, calcium, barium, and strontium by electrolysis but his priority was disputed. In 1810 he published a paper on chlorine, which established that it contained no oxygen – another blow against the oxygen theory of acidity – and was in fact an element. The name ‘chlorine’ was proposed by Davy.In 1812 Davy was knighted, married a wealthy widow, and published his book Elements of Chemical Philosophy. In 1813 he appointed Michael Faraday as his assistant and the Davys and Faraday visited France. Working in Michel Chevreul's laboratory, he established that iodine, discovered two years before by Bernard Courtois, was an element similar in many properties to but heavier than chlorine. On his return to England, Davy was commissioned to investigate the problem of firedamp (methane) explosions in mines. In 1816, only six months after beginning the investigation, he produced the famous safety lamp, the Davy lamp, in which the flame was surrounded by a wire gauze.Davy became president of the Royal Society in 1820 and the rest of his life was much taken up by traveling on the Continent. Despite his successes there is something incomplete about his life. He never accepted the atomic theory of Dalton, his great contemporary. He had in fact more in common with his Romantic poet friends than he did with Dalton. Jöns Berzelius said of him that his work consisted of “brilliant fragments.”
Scientists. Academic. 2011.