Paul-Émile Lecoq de Boisbaudran

Paul Émile (François ) Lecoq de Boisbaudran ( born April 18, 1838 in Cognac, † May 28, 1912 in Paris) was a French chemist.

Life and work

The son of a wine merchant's family grew up in an era marked by friendliness, mutual respect and personal responsibility atmosphere. His mother taught him in foreign languages ​​and history. In the self-study, he used this teaching documents of the École Polytechnique, he gained a solid background in chemistry and physics. With the help of his uncle, he set up a private laboratory where he conducted various experiments in addition to his work in the family business and in 1875 the chemical element Gallium - named for patriotic or selfish reasons so - discovered.

Due to its physico-chemical work in the field of Gustav Robert Kirchhoff and Robert of Wilhelm Bunsen ( 1859) developed radio spectroscopy Boisbaudran quickly became known and a recognized authority. He developed a theory about the relation between frequency of the spectral lines and atomic mass of a chemical element. Based on the lack of lines in the spectrum of aluminum and indium he tried early on to find a previously unknown element, that would be somewhere between the two elements. But all attempts failed due to the small amount of the isolated substance. About the prediction of this first known as eka- aluminum element by Mendeleev in 1871 Boisbaudran according to his own statement has learned nothing. So he took his time with the other equipment of his laboratory and began in 1874 with the work-up of 54 kg of a sphalerite ( zinc ore ) from Pierrefitte in the Pyrenees, which he had purchased in 1868. In September 1875, he was the first time demonstrate, by a spectral line the searched element. In the same month, he traveled to Paris, where for his new element in the laboratory of Charles Adolphe Wurtz. Here he met among others also know Charles Friedel. In November succeeded Boisbaudran produce the first metallic gallium by electrolysis of ammoniacal gallium solution. After a short time he had made ​​a sufficient amount of substance in order to determine the physical properties. In 1876, he collaborated with his colleague Émile Jung meat on four tons of sphalerite and won it 75 g of metallic gallium.

Later Boisbaudran turned to the rare earth metals and discovered the elements samarium in Samarskite (1879 ) and dysprosium in the Holmiumerde ( 1886).

After 1895, he could not perform experimental work more because of ankylosis ( stiffening of the joints ).

Writings

  • Spectres lumineux: specters prismatiques et d' ondes en longueurs destinés aux recherches de chimie minérale. Gauthier -Villars, Paris 1874

Awards

  • " prix Bordin " of the Académie of Sciences ( 1872),
  • The award of the Légion d' Honneur ( Legion of Honor ) à la Sorbonne (1876 ),
  • Les palmes académiques ( academic palm),
  • Le titre de correspondant de l' institut (10 June 1878),
  • Grand Prix of the 1878 World Fair
  • Davy Medal of the Royal Society in London (1879 )
  • The 10 000 francs doped " prix Lacaze " by the Academy of Sciences ( 1880)
Cognac, France France Aluminium Rare earth element Exposition Universelle (1878) Integrated Authority File
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