Paul Emile Lecoq de Boisbaudran

Physical chemist, born in Cognac, W France. A founder of spectroscopy, he discovered gallium, samarium, and dysprosium.

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

In 1874 he wrote Spectres lumineux, spectres prismatiques, et en longeurs d'ondes destines aux recherche de chimie minerale, which was published in Paris by Gauthier-Villars and was one of the first descriptions of the new science of spectroscopy developed by Kirchhoff. In 1875 he used this method to discover the element gallium, which he named after the Latin word for Gaul, Gallia. It was later claimed that Lecoq had named the element after himself, since gallus is the Latin translation of the French le coq, but Lecoq denied this in an article of 1877.

Lecoq contributed further to the development of the periodic classification of elements by proposing, soon after its discovery, that argon was a member of new, previously unsuspected, group of elements, later to become known as the noble gases.