Humphry Davy

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Sir Humphry Davy, 1st Baronet FRS (17 December 1778 – 29 May 1829) was a British chemist and physicist. He is probably best remembered today for his discoveries of several alkali and alkaline-earth elements, as well as contributions to the discoveries of the elemental nature of chlorine and iodine. He invented the Davy lamp, which proved a boon to miners. Berzelius called Davy's 1806 Bakerian Lecture On Some Chemical Agencies of Electricity "one of the best memoirs which has ever enriched the theory of chemistry. This paper was central to any chemical affinity theory in the first half of the nineteenth century.

Early Life

Davy was born in Penzance, Cornwall, and both his brother John Davy and cousin Edmund Davy were also noted chemists.

Public life and work

Sir Humphry revelled in his public status, as his lectures gathered many spectators. He became well known due to his experiments with the physiological action of some gases, including laughing gas (nitrous oxide) - to which he was addicted, once stating that its properties bestowed all of the benefits of alcohol but was devoid of its flaws. Davy later damaged his eyesight in a laboratory accident with nitrogen trichloride. In 1801 he was nominated professor at the Royal Institution of Great Britain and Fellow of the Royal Society, over which he would later preside.

Retirement and further work

In 1812 he was knighted, gave a farewell lecture to the Royal Institution, and married a wealthy widow, Jane Apreece. (While generally acknowledged as being faithful to his wife, their relationship was stormy and in his later years Davy travelled to continental Europe alone.) In October 1813 he and his wife, accompanied by Michael Faraday as his scientific assistant (and valet) traveled to France to collect a medal that Napoleon Bonaparte had awarded Davy for his electro-chemical work. Whilst in Paris Davy was asked by Gay-Lussac to investigate a mysterious substance isolated by Bernard Courtois. Davy showed it to be an element, which is now called iodine. The party left Paris in December, travelling south to Italy.

They sojourned in Florence, where, in a series of experiments conducted with Faraday's assistance, Davy succeeded in using the sun's rays to ignite diamond, proving it is composed of pure carbon. Davy's party continued on to Rome, and also visited Naples and Mount Vesuvius. By June 1814, they were in Milan, where they met Alessandro Volta, and continued north to Geneva. They returned to Italy via Munich and Innsbruck, but their plans to travel to Greece and Constantinople (Istanbul) were abandoned after Napoleon's escape from Elba, and they returned to England.

In 1818, Davy was awarded a baronetcy, and two years later he became President of the Royal Society.

Davy lamp

After his return to England in 1815, Davy perfected the Davy lamp which was widely used by miners. Although the idea of the safety lamp had already been demonstrated by William Reid Clanny and an engineer, George Stephenson, Davy's use of wire gauze to prevent the spread of flame was quickly copied by both of these inventors in their later designs.

Discovery of chlorine

He also showed that oxygen could not be obtained from the substance known as oxymuriatic acid and proved the substance to be an element, which he named chlorine. (However Carl Scheele is credited as the discoverer of chlorine. Scheele had discovered it 36 years before Davy, but was unable to publish his findings.) This discovery overturned Lavoisier's definition of acids as compounds of oxygen.

Acid-base studies

In 1815 Davy suggested that acids were substances that contained replaceable hydrogen – hydrogen that could be partly or totally replaced by metals. When acids reacted with metals they formed salts. Bases were substances that reacted with acids to form salts and water. These definitions worked well for most of the nineteenth century.

Electrolysis

Davy was also a pioneer in the field of electrolysis and found that lithium acts as an electrolyte and provides electrical energy. The battery works by the reverse process to electrolysis.

Death and legacy

Davy died in Switzerland in 1829, his various inhalations of chemicals finally taking their toll on his health. He is buried in the Plain Palais Cemetery in Geneva.

Davy's laboratory assistant, Michael Faraday, went on to enhance Davy's work and in the end became more famous and influential – to such an extent that Davy is supposed to have claimed Faraday as his greatest discovery. However, he later accused Faraday of plagiarism, causing Faraday (the first Fullerian Professor of Chemistry) to cease all research in electromagnetism until his mentor's death.

Memorial honours

A lunar crater (Davy) is named after Sir Humphry Davy. It has a diameter of 34 km and coordinates of 11.8S, 8.1W.

In Penzance in Cornwall, Davy's hometown, there is a statue of him in front of the imposing Market House, now owned by Lloyds TSB, at the top of Market Jew Street, the town's main high street.

There also is a secondary school in Penzance named Humphry Davy School. Like James Prescott Joule and Isaac Newton, Davy is remembered in his hometown by a pub. The Sir Humphry Davy pub is located in Penzance opposite the Greenmarket at the end of Market Jew Street.

Davy was the subject of the first ever clerihew.

A satellite of the University of Sheffield at Golden Smithies Lane in Wath upon Dearne (Manvers) is called Humphry Davy House and is currently home to the School of Nursing and Midwifery, until April 2009.

Writings by Davy

See Fullmer's work for a full list of Davy's articles. Davy's books are as follows:

Researches, Chemical and Philosophical, Bristol: Biggs and Cottle, 1800
Elements of Chemical Philosophy, London: Johnson and Co., 1812
Elements Of Agricultural Chemistry In A Course Of Lectures, London, Longman, 1813
The Papers of Sir H. Davy, Newcastle: Emerson Charnley, 1816 (on Davy's safety lamp)
Discourses to the Royal Society, London: John Murray, 1827
Salmonia: Or Days of Fly Fishing, London: John Murray, 1828
Consolations in Travel: Or the Last Days of a Philosopher, London: John Murray, 1830

References

External links

Works by Humphry Davy at Project Gutenberg
Elements of Chemical Philosophy by Humphry Davy (1812)
Salmonia or Days of Fly Fishing by Humphry Davy (1828)
Consolations in Travel or The Last Days of a Philosopher by Humphry Davy (1830)
Obituary (1830)
Dictionary of National Biography (1888)
Humphry Davy, Poet and Philosopher by Thomas Edward Thorpe, New York: Macmillan, 1896
Young Humphry Davy: The Making of an Experimental Chemist by June Z. Fullmer, Philadelphia: American Philosophical Society, 2000

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