Spectroscopy

Lecoq was very impressed by the new science of spectroscopy, which was used to discover the element helium. The pattern made by light reflected from a rock could be used to find out what elements were present in it. So if there was an unknown pattern, was it an unknown element?

Discovery of gallium

The Russian chemist Mendeleev had predicted in 1871 that there was a new element called - eka-aluminium waiting to be discovered. Lecoq decided to look for it. After four years of trying, he found it in a sample of zinc ore from the Pyrenees mountains by spectroscopy. He spent the next year trying to purify it, till he succeeded in getting enough of it in a pure condition for analysis. When he did chemical tests on it, it behaved almost exactly like Mendeleev said it would.

He wrote a letter to Mendeleev explaining his new discovery. Mendeleev wrote back saying that he had made a few errors in his experiments. When Lecoq checked them, he found Mendeleev was right. What he had discovered truly was eka-aluminium, and that meant that Mendeleev's prediction were correct.

Lecoq named the element gallium after Gallia, the Latin name for France. But some folk say that he actually named it after himself. For 'le coq' is the French word for 'the rooster', and the Latin word for it is 'gallus'. But Lecoq denied the allegation in an article on gallium he wrote in 1877.

Discovery of other elements

In the following years, he discovered the elements samarium and dysprosium, which are rare earth metals used in electronics. He also succeeded in purifying gadolinia, (the oxide of gadolinium) which had been discovered by the Swiss chemist Marignac. In 1894, the British chemist Ramsay had discovered argon. Lecoq pointed out that argon and helium were so different from other elements that formed a completely new set in the periodic table, later to be known as 'Noble Gases'.

Life

He was born Paul Emile Lecoq de Boisbaudran on 18^th April, 1838 in Cognac, France. But he is better known as Francois Lecoq. His family were the seigneurs (similar to zamindars) of Boisbaudran, and thus quite rich and respected in the country. Though the family's main business was wine-making, Francois preferred to study chemistry.

He studied at the Ecole Polytechnique in Paris, under the organic chemist Charles-Adolphe Wurtz. But he soon shifted from organic to inorganic chemistry, excited by the upcoming science of spectroscopy. He got interested in the discovery of new elements, and set up his own private laboratory in Paris to do his research.

In 1876, he was awarded the Chevalier of the Legion d'Honneur, one of France's highest awards, for his discovery of gallium. In 1879, he got the Davy Medal of the Royal Society of London. He died in 1912.