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Humphry Davy

2007 Schools Wikipedia Selection. Related subjects: Chemists

   CAPTION: Sir Humphry Davy

   Sir Humphry Davy
   Sir Humphry Davy
         Born       December 17, 1778
                    Penzance, Cornwall, United Kingdom
         Died       May 29, 1829
                    Geneva, Switzerland
        Field       Physicist and Chemist
     Institution    Royal Institution
   Notable students Michael Faraday
      Known for     Electrolysis, Chlorine, Davy lamp

   Sir Humphry Davy, 1st Baronet, FRS ( 17 December 1778 – 29 May 1829)
   was an esteemed British chemist and physicist. He was born in Penzance,
   Cornwall, United Kingdom and both his brother John Davy and cousin
   Edmund Davy were also noted chemists. 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 ninteenth century.

Biography

   Sir Humphry revelled in his status, as his lectures gathered many
   spectators. Davy 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. He later invented the davy lamp which was
   a great and well known success. He discovered the element barium.

Electrochemistry work

   Humphry Davy in his youth.
   Humphry Davy in his youth.

   In 1800, Alessandro Volta announced his invention of the first electric
   pile or battery. Davy used this electric battery to separate salts by
   what is now known as electrolysis. With many batteries in series he was
   able to separate elemental potassium and sodium in 1807 and calcium,
   strontium, barium, and magnesium in 1808, which is when he also
   discovered and named aluminium. He also studied the energies involved
   in separating these salts, which is now the field of electrochemistry.
   According to the historian Christopher Lawrence, in the book
   Romanticism and the Sciences, his electrolytic work was driven by
   Romantic beliefs in a unity in nature, composed of polar forces.

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 Barnard Courtois. Davy showed it to be
   an element, which is now called iodine. The party left Paris on
   December 29, travelling south through Montpellier and Nice and then to
   Italy.

   After passing through Genoa, they went to Florence, where, in a series
   of experiments starting on Sunday March 27, Davy, with Faraday's
   assistance, succeed in using the sun's rays to ignite diamond, and
   proved that it was composed of pure carbon. Davy's party continued on
   to Rome, and also visited Naples and Mount Vesuvius. By the June 17,
   they were in Milan, where they met Alessandro Volta, and continued
   north to Geneva. They returned to Italy via Munich and Innsbruck,
   passed though Venice and returned to Rome. Their plans to travel to
   Greece and Constantinople (Istanbul) were abandoned after Napoleon's
   escape from Elba, and they returned to England.

Davy lamp

   After his return to England in 1815, Davy went on to produce the Davy
   lamp which was used by miners, although there is evidence to show that
   Davy "invented" his device at about the same time as an engineer,
   George Stephenson, but claimed all the credit for the invention.

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 and bases 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 century. Today we use the
   Brønsted-Lowry theory of acids and bases.

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

Further electrochemistry studies

   In 1824 he proposed and eventually mounted chunks of iron to the hull
   of a copper clad ship in the first use of cathodic protection. Whilst
   this was effective in preventing the corrosion of copper, it eliminated
   the anti-fouling properties of the copper hull, leading to the
   attachment of molluscs and barnacles to the "protected" hull, slowing
   these ships and requiring extensive time in dry docks for defouling
   operations.He discoverd Calcium in 1808 in London England.

Death

   Davy died in Switzerland in 1829, his various inhalations of chemicals
   finally taking its 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.

Davy's Statue

   Statue of Sir Humphry Davy located at Market Jew Street, Penzance,
   Cornwall
   Statue of Sir Humphry Davy located at Market Jew Street, Penzance,
   Cornwall

   In the town of Penzance in Cornwall a statue of Davy, its most famous
   son, stands 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.

School

   There is a secondary school in Penzance named Humphry Davy School

Miscellanea

     * Davy was the subject of the first ever clerihew:

          Sir Humphry Davy
          Abominated gravy.
          He lived in the odium
          Of having discovered sodium.

     * Like James Prescott Joule and Isaac Newton, Davy is remembered in
       his hometown by a local pub. The Sir Humphry Davy pub is located in
       Penzance opposite the Geenmarket at the end of Market Jew Street.

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

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