Humphry Davy

Sir Humphry Davy (sometimes misspelled " Humphrey " ) ( born December 17, 1778 in Penzance, Cornwall, England; † May 29, 1829 in Geneva ) was an English chemist. From 1802 to 1812 he was professor of chemistry at the Royal Institution in London. By electrolysis of molten alkali succeeded for the first time to describe the elements sodium, potassium, barium, strontium, calcium and magnesium. Davy recognized the chlorine as an element. It was a prerequisite for acids in the presence of hydrogen. He thus became one of the pioneers of modern electrochemistry.


From 1802 to 1812 Davy was a professor of chemistry at the Royal Institution in London. Here he gave public experimental lectures on chemistry and agricultural chemistry. Davy was very interested in soon for the Voltaic pile and electrolytic phenomena. In November 1807 Davy became seriously ill and could give lectures again until March 1808.

After elevation to the peerage in 1812 Davy gave up his professorship at the Royal Institution, his successors were William Thomas Brande and later Michael Faraday.

Scientific work

Davy was an outstanding chemist in the first half of the 19th century. As one of the first he used electrical current from the voltaic pile for chemistry experiments. Davy established the formation of acids and bases by the electrolysis with the presence of salts or contaminants. In pure water remained in the formation of acids and bases in his experiments. He also examined the rate of migration of acids and bases in electrolysis.

Potassium, sodium

So far it was assumed that alkali salts would be indivisible and elementary. Davy was able to convert with a fused-salt electrolysis in the metallic elements sodium potassium by means of the voltaic pile sodium hydroxide and potassium hydroxide. Alkali metals burn and explode in the water.

And the new elements chlorine, bromine, iodine, fluorine, - oxygen-free acids, hydrogen halides

By electrolysis of brine he had isolated the chlorine, the chlorine reacted with hydrogen to form hydrogen chloride. After Claude -Louis Berthollet and Antoine Lavoisier all acids (the name of the element therefore ) should also hydrochloric acid oxygen.

Davy now recognized the hydrogen and not oxygen as an essential feature of all acids. A similar view was Pierre Louis Dulong (1785-1838) in 1815, almost simultaneously, before.

Davy, Michael Faraday first set institution as an assistant at the Royal, enabling whose scientific career.

An important factor in farming research were his London Experimental lectures on agricultural chemistry, in which he summarized all the knowledge in this area critical. The text of these lectures was published in 1813 in book form under the title Elements of Agricultural Chemistry. Especially the one year later published German -language edition has numerous scientists in Germany encouraged to further integrate methods and problems of young agricultural chemistry in the traditional farming research.


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

The lunar crater Davy is named after him.


  • Elements of Agricultural Chemistry, in a Course of Lectures for the Board of Agriculture. London 1813.
  • Volume 2: Early miscellaneous papers from 1799 to 1805, with an introductory lecture and outlines of lectures on chemistry, delivered in 1802, 1804 and 1839 (online)..
  • Volume 4: Elements of Chemical Philosophy. 1840 ( online).
  • Volume 7: Discourses delivered before the Royal Society: Elements of Agricultural Chemistry, Part I. 1840 ( online).
  • Volume 9: Salmonia, or Days of fly-fishing / Consolation in travel, or The last days of a philosopher. 1840 ( online).
  • Electrochemical studies. Ostwald's classic of the exact sciences. Vol 45, Eds: W. Ostwald. Leipzig 1893.