Johann Wolfgang Döbereiner

Johann Wolfgang Döbereiner
Johann Wolfgang Döbereiner

Johann Wolfgang Döbereiner
Born December 13, 1780
Hof, Bayreuth
Died March 24, 1849
Jena
Nationality German
Fields Chemistry
Known for Döbereiner's triads
Döbereiner's lamp

Johann Wolfgang Döbereiner (December 13, 1780 – March 24, 1849) was a German chemist who is best known for work that foreshadowed the periodic law for the chemical elements.

Life and work

As a coachman's son, Döbereiner had little opportunity for formal schooling, and so he was apprenticed to an apothecary, reading widely, and attending science lectures. He eventually became a professor at the University of Jena in 1810. In work beginning in 1829,[1] Döbereiner discovered trends in certain properties of selected groups of elements. For example, the average atomic mass of lithium and potassium was close to the atomic mass of sodium. A similar pattern was found with calcium, strontium, and barium, with sulphur, selenium, and tellurium, and also with chlorine, bromine, and iodine. Moreover, the densities for some of these triads followed a similar pattern. These sets of elements became known as "Dobereiner's Triads".[2][3]

Döbereiner also is known for his discovery of furfural, for his work on the use of platinum as a catalyst, and for a lighter, known as Döbereiner's lamp.

The German writer Goethe was a friend of Döbereiner, attended his lectures weekly, and used his theories of chemical affinities as a basis for his famous 1809 novella Elective Affinities.


World of Scientific Discovery on Johann Wolfgang Döbereiner


The earliest years of Döbereiner's life did not suggest a brilliant future. He was born in Hof, Bavaria, on December 13, 1780, of poor parents. His father was a coachman who could provide Johann with only the most basic education. Although Döbereiner did attend a few lectures in chemistry, botany, mineralogy, philosophy, and languages, he was largely self-taught. Yet, he developed unusual skill in chemical research and caught the eye of Duke Carl August in 1810. Duke Carl appointed Döbereiner to the position of professor extraordinary in chemistry at Jena, a position he held throughout the rest of his academic life. Döbereiner was a man of far-ranging interests and accomplishments. He conducted research on the manufacture of vinegar, the abundance of elements in the Earth's crust, the use of mineral waters for medical purposes, and many other topics in general, pharmaceutical, and analytical chemistry. In 1831 he discovered the chemical compound furfural, obtained from corn cobs, oat and rice hulls, and other cellulose-containing materials. He was one of the first chemists to offer laboratory instruction in chemistry. In the early 1820s, Döbereiner studied the role of platinum metal as a catalyst. Somewhat earlier, Sir Humphry Davy had observed that heated platinum wire greatly increased the rate at which organic compounds oxidize. Döbereiner's contribution was to show that finely divided platinum ("platinum sponge") was even more effective than was solid platinum metal. He even invented a lighter that would generate a flame when gaseous hydrogen came into contact with a spongy platinum catalyst. Most students recognize Döbereiner's name, however, for his contribution to the development of the periodic law. One consequence of Jöns Berzelius ' work on atomic weights was the realization by chemists that the properties of elements might be related to these atomic weights. Around 1817, Döbereiner noticed a pattern among three elements with similar chemical properties, chlorine, bromine, and iodine. Specifically, he noted that the atomic weight of bromine (80.970) was the arithmetic mean of the atomic weights of chlorine (35.470) and iodine (126.470). The currently accepted atomic weight for bromine was 80.470. Furthermore, the properties of the three elements varied in an orderly manner, from chlorine to bromine to iodine. Döbereiner spoke of this group of elements as a triad. He found two other triads among the known elements. One triad consisted of calcium, strontium, and barium; the other of sulfur, selenium, and tellurium. Other chemists attempted to find other triads among the elements, but, overall, Döbereiner's discovery seemed to be a dead end. Thus, chemists largely ignored the Law of Triads. Not until Dmitri Mendeleev's discovery of the periodic law four decades later did the significance of Döbereiner's discovery finally become apparent. Döbereiner died at Jena on March 24, 1849, twenty years before Mendeleev published his periodic law.

References

  1. ^ http://chemed.chem.purdue.edu/genchem/history/dobereiner.html
  2. ^ "Johann Wolfgang Dobereiner". http://chemed.chem.purdue.edu/genchem/history/dobereiner.html. Retrieved 2008-03-08. 
  3. ^ "A Historic Overview: Mendeleev and the Periodic Table". http://genesismission.jpl.nasa.gov/educate/scimodule/UnderElem/UnderElem_pdf/HistOverST.pdf. Retrieved 2008-03-08. 

Further reading


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