Sunday, January 1, 2012
Damacay established a private laboratory in Paris where he became an expert reading the spectra of inorganic elements. It was said that, he could read a spectra "like the score of an opera". He built an spark spectrum instrument which allowed him to purify and study rare earth elements. Rare earth elements are a group of metallic elements which include scandium, yttrium, and the entire lanthanide series of elements. Despite their name they are relatively common (with the exception of promethium which is radioactive) but because of their geo-chemical properties they are not found in large, economically exploitable amounts. Today China is the world leader in the production and export of these elements, which are used in the manufacture of electronics.
In 1898 when Marie and Pierre Curie isolated the radioactive element polonium, they saw that the sample from which it had been removed remained radioactive. The Curies took their remaining radioactive sample to Demarcay for analysis. Demarcay examined the spectra of the sample and determined that there was a spectral line unaccounted for and told the Curies there was an new element in their sample. This spectral line was caused by radium in their sample, which the Curies were eventually able to isolate in 1902.
Demarcay is most famous for the discovery of the rare earth element europium. In 1892 Paul Boisbaudran while working with a sample of the element samarium, which he had discovered, found a spectral line not accounted for. Demarcay examined spectra of samples of samarium and gadolinium and proposed that there was an undiscovered element between them on the periodic table. Using a crystallization technique of his own invention Demarcay was able to isolate the new element in 1902, which he named europium, after the continent of Eruope.
The date of his death in many references is incorrect. Demarcay died on March 5, 1903.
Daintith, John, editor; "Demarcay, Eugene Anatole (1854-1904)" in Biographical Dictionary of Scientists Third Edition; CRC Press, 2008
Marshall, John L. and Marshall, Virginia R.; "Discovery of the Elements: Europium-Eugene Demarcay"; The Hexagon; Summer 2003, p.19-21
Eugene-Anatole Demarcay Wikipedia Entry