Humphry Davy

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Humphry Davy on a painting by Thomas Phillips (1770–1845) from 1821
Humphry Davy based on a painting by Henry Howard from 1803

Sir Humphry Davy, 1st Baronet (sometimes incorrectly spelled "Humphrey"; * December 17, 1778 in Penzance , Cornwall , England ; † May 29, 1829 in Geneva ) was an English chemist and is known, among other things, for the discovery of the pain-relieving effect of laughing gas . From 1802 to 1812 he was Professor of Chemistry at the Royal Institution in London. Davy recognized chlorine as an independent element and thus that hydrogen, not oxygen, gives acids their special chemical properties. By electrolysis of molten alkalis , he succeeded for the first time in representing the elements sodium , potassium , barium , strontium , calcium and magnesium . He is one of the pioneers of modern electrochemistry .

Life

Davy was the son of a wood carver and initially apprenticed to a surgeon and pharmacist in his hometown (1794). As an autodidact, he acquired extensive knowledge in the fields of chemistry and physics. In an experiment he was able to prove that heat is not material. Now he got a job in the "Pneumatic Institute" founded by Thomas Beddoes in Bristol . The institute studied the healing effects of gases, but many of the gases examined were very toxic. During experiments in the laboratory in Bristol, he discovered in self-experiments carried out between 1795 and 1798 the intoxicating and analgesic effects of nitrous oxide , which he used to treat toothache. In his description of the effects of nitrous oxide, published in 1800, he also recommended it for use in surgical operations. In 1798 Beddoes commissioned him to manage the "Pneumatic Institute".

From 1802 to 1812 Davy was Professor of Chemistry at the Royal Institution in London. Here he gave public experimental lectures on chemistry and agricultural chemistry . Davy soon became interested in the voltaic column and electrolytic phenomena. Davy fell seriously ill in November 1807 and was only able to give lectures again in March 1808.

In order to receive his research award in electrochemistry, he received an entry permit from Napoleon to France and there came into contact with André-Marie Ampère .

After he was raised to the nobility in 1812, Davy renounced his professorship at the Royal Institution, his successors were William Thomas Brande and later Michael Faraday .

From 1813 to 1815 he undertook a trip through continental Europe with Faraday as Amanuensis with the permission of the French government .

From 1820 to 1827 he was President of the Royal Society . In this position he was one of the most influential scientists in England at the time, but his health was already badly damaged at this stage. The multitude of his experiments, obligations and the inhaled toxins had damaged his health very early on. After two strokes, he died at the age of 50 in Geneva, where he was also buried.

Scientific work

Davy was an eminent chemist in the first half of the 19th century. He was one of the first to use electricity from the voltaic column for chemical experiments. Davy justified the formation of acids and bases during electrolysis with the presence of salts or impurities. In his experiments in pure water the formation of acids and bases did not occur. He also examined the migration speed of the ions of acids and bases during electrolysis.

Sodium, potassium

Until now it had been assumed that alkali salts were indecomposable and elementary. Davy was able to convert sodium hydroxide and potassium hydroxide into the metallic elements sodium and potassium by means of a fused-salt electrolysis using the Voltasch column .

The new elements chlorine, bromine, iodine, fluorine - oxygen-free acids, hydrogen acids

He isolated the chlorine by electrolysis of saline solution, and the chlorine reacted with hydrogen to form hydrogen chloride . According to Claude-Louis Berthollet and Antoine Lavoisier , all acids, including hydrochloric acid, should contain oxygen (hence the name of the element).

Davy, Gay-Lussac and Thenard examined the hydrogen chloride with strong reducing agents. However, they could not detect any oxygen in the gas. Davy postulated that chlorine gas was a chemical element and not a compound. Gay-Lussac and Thenard were soon convinced that this assumption was correct. Also, iodine , bromine and chlorine have been recognized as new elements.

Davy now recognized hydrogen and not oxygen as an essential characteristic of all acids. Pierre Louis Dulong (1785–1838) put forward a similar view in 1815, almost at the same time.

Alkaline earth metals, miscellaneous

Mining lamp , after Davy ( Davy safety lamp )

By electrolysis of molten alkaline earths , he succeeded in representing the elements barium , strontium , calcium and magnesium . Davy is one of the pioneers of modern electrochemistry . He also created the chemical prerequisites for later photography. Among other things, he discovered the light-sensitive silver iodide . Davy also discovered phosphorus trichloride , phosphorus pentachloride and chlorine dioxide .

One of his most important technical inventions was a miner's lamp used to indicate firedamp in mining ( Davy safety lamp ); he also dealt with electrically operated lamps: in 1802 he conducted electricity through a platinum thread and made it glow. In 1809 he developed the first arc lamp (see also: Aphloghistic lamp ).

He found a method to protect the copper on sailing ships against weathering (by attaching a zinc sheet , see also sacrificial anode ). However, Davy never applied for a patent.

Davy also calculated the number of oxygen atoms in the atmosphere. According to his calculations, the supply was so large that a billion people - without photosynthesis - would have had enough oxygen to breathe for several million years.

Davy initially hired Michael Faraday as an assistant at the Royal Institution, thus making his academic career possible.

His London experimental lectures on agricultural chemistry , in which he critically summarized all knowledge in this area, were important for agricultural research . The text of these lectures was published as a book in 1813 under the title Elements of Agricultural Chemistry . In particular, the German-language edition, which appeared a year later, encouraged numerous scientists in Germany to integrate methods and issues of young agricultural chemistry more strongly into traditional agricultural research.

1807 he was the mathematical-physical class of the French National Institute of of Napoleon Bonaparte exposed Galvanic Price awarded by 3000 francs.

Davy spoke several European languages, loved aesthetic literature and worked himself as a poet.

Honors

Monument in Penzance

In 1812 he was knighted . On October 20, 1818 he was given the hereditary title of Baronet , of Grosvenor Street, in the Parish of Saint George, Hanover-Square , in the County of Middlesex , because he remained childless, this title expired on his death in 1829. 1803 became he was elected as a member (" Fellow ") in the Royal Society , which gave him the Copley Medal in 1805 , the Rumford Medal in 1816 and the Royal Medal in 1827 . In 1808 he became a Fellow of the Royal Society of Edinburgh . Since 1810 he was an elected member of the American Philosophical Society . In 1813 he was elected to the Académie des Sciences , 1820 to the Bavarian Academy of Sciences , 1822 to the American Academy of Arts and Sciences and 1823 to the Göttingen Academy of Sciences .

In Davy's birthplace Penzance , a statue in the city center commemorates one of the city's most famous sons.

The moon crater Davy is named after him.

Fonts

English editions

  • Elements of Agricultural Chemistry, in a Course of Lectures for the Board of Agriculture. London 1813.
  • Consolations in Travel or The Last Days of a Philosopher. John Murray, London 1830 ( books.google.de ).
  • Researches, Chemical and Philosophical, chiefly concerning Nitrous Oxide, or dephlogisticated Nitrous Air, and its Respiration. London 1800 ( digitized version )
  • John Davy (Ed.): The Collected Works of Humphry Davy. 9 volumes, Smith, Elder & Co., London 1839–1840.
    • Volume 1: Memoirs of the Life of Sir Humphry Davy . 1839 ( archive.org ).
    • Volume 2: Early miscellaneous papers from 1799 to 1805, with an introductory lecture and outlines of lectures on chemistry, delivered in 1802, and 1804. 1839 ( books.google.de ).
    • Volume 3: Researches, Chemical and Philosophical, chiefly concerning Nitrous Oxide, or dephlogisticated Nitrous Air, and its Respiration. 1839 ( books.google.de ).
    • Volume 4: Elements of Chemical Philosophy. 1840 ( archive.org ).
    • Volume 5: Bakerian Lectures and Miscellaneous Papers from 1806 to 1815. 1840 ( archive.org ).
    • Volume 6: Miscellaneous Papers and Researches, especially on the Safety-Lamp, and Flame, and on the Protection of the Copper Sheathing of Ships, from 1815 to 1828. 1840 ( books.google.de ).
    • Volume 7: Discourses delivered before the Royal Society: Elements of Agricultural Chemistry, Part I . 1840 ( archive.org ).
    • Volume 8: Elements of Agricultural Chemistry, Part II / Miscellaneous lectures and extracts from lectures. 1840 ( books.google.de ).
    • Volume 9: Salmonia, or Days of fly-fishing / Consolation in travel, or The last days of a philosopher. 1840 ( archive.org ).

German editions

  • Elements of agricultural chemistry in a series of lectures given to the Society for the Advancement of Agriculture. Translated from English by Friedrich Wolff, accompanied by comments and a preface by the Royal Prussian Councilor Albrecht Thaer. Berlin 1814.
  • Sir Humphry Davy's Comforting Remarks on Travel, or the Last Days of a Naturalist. Aslant. Nuremberg 1833 ( digitized version )
  • Electrochemical investigations. In: W. Ostwald (Ed.): Ostwald's classics of exact sciences. Volume 45. Leipzig 1893.
  • About the safety lamp. In: K. Clusius (Ed.): Ostwald's classics of the exact sciences. Volume 242. Leipzig 1937.

literature

Web links

Commons : Humphry Davy  - album with pictures, videos and audio files

Individual evidence

  1. ^ Rudolf Frey , Otto Mayrhofer , with the support of Thomas E. Keys and John S. Lundy: Important data from the history of anesthesia. In: R. Frey, Werner Hügin , O. Mayrhofer (Ed.): Textbook of anesthesiology and resuscitation. Springer, Heidelberg / Basel / Vienna 1955; 2nd, revised and expanded edition. With the collaboration of H. Benzer. Springer-Verlag, Berlin / Heidelberg / New York 1971. ISBN 3-540-05196-1 , pp. 13–16, here: p. 14.
  2. ↑ Philos. Transact. 1810, p. 231.
  3. ↑ Memoires de la Societe d'Arcueil. 2, p. 339.
  4. ↑ Philos. Transact. 1811, p. 1.
  5. ^ Annual reports on advances in chemistry. 6, p. 185.
  6. ↑ Practitioners of the 19th century. (PDF; 303 kB)
  7. ↑ History of technology ( Memento of October 6, 2007 in the Internet Archive ) (PDF; 1.1 MB)
  8. ^ Concise dictionary of chemistry. Verlag Friedrich Vieweg and Son, Braunschweig 1842, keyword: “Atmosphere”, p. 562.
  9. ^ Ernest Maindron: Les fondations de prix à l'Académie des sciences. Les lauréats de l'Académie 1714-1880. Gauthier-Villars, Paris 1881, pp. 69-70 ( gallica.bnf.fr ).
  10. ^ The London Gazette : 17410, 1875 , October 20, 1818.
  11. ^ Fellows Directory. Biographical Index: Former RSE Fellows 1783–2002. Royal Society of Edinburgh, accessed October 20, 2019 .
  12. ^ Member History: Humphry Davy. American Philosophical Society, accessed July 7, 2018 .
  13. ↑ Sir Humphry Davy's membership entry at the Bavarian Academy of Sciences , accessed on January 16, 2017.
  14. ↑ Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 65.
personal data
SURNAME Davy, Humphry
ALTERNATIVE NAMES Davy, Humphrey (misspelling); Davy, Sir Humphry, 1st Baronet
BRIEF DESCRIPTION English chemist
DATE OF BIRTH December 17, 1778
PLACE OF BIRTH Penzance , Cornwall , England
DATE OF DEATH May 29, 1829
Place of death Geneva