Marc Delafontaine, Date of Birth, Place of Birth, Date of Death

Marc Delafontaine

Swiss chemist (1838-1911)

Date of Birth: 31-Mar-1838

Place of Birth: Céligny, Canton of Geneva, Switzerland

Date of Death: 01-Jan-1911

Profession: chemist, university teacher

Nationality: Switzerland

Zodiac Sign: Aries

Marc Delafontaine (March 31, 1837/1838, Céligny, Switzerland–1911) was a Swiss chemist and spectroscopist who in 1878, along with Jacques-Louis Soret, first observed holmium spectroscopically.
In 1879, Per Teodor Cleve chemically separated it from thulium and erbium.
All three men are given credit for the element's discovery.In 1843 Carl Gustaf Mosander discovered terbium and erbium as components of yttria. However, this discovery was hotly contested.
Spectroscopist Nils Johan Berlin denied that the two elements existed, failing to confirm the existence of "erbia" and suggesting that its name be applied to "terbia".
In 1864, Marc Delafontaine used optical spectroscopy to conclusively prove that yttrium, terbium and erbium were separate elements.
Ironically, however, the confusion that had been introduced between the names continued.
Mosander's proposed names were switched, giving the amethyst compound the name "erbium" oxide and the yellow substance the name "terbium" oxide, instead of the other way around as originally proposed.Delafontaine studied with Jean Charles Galissard de Marignac at the University of Geneva.
He worked at the University of Geneva, and later moved to the United States of America where he became a naturalized citizen.
He taught at a women's college in Chicago, Illinois.