Jean Charles Galissard De Marignac
Date of Birth: 04/24/1817
Place of birth: Geneva
He graduated in 1839, the Paris Higher Mining School; Professor, University of Geneva (1841-78).
In 1866-1877 gg. he led a fierce controversy with Saxon chemist Joseph R. Hermann, which denied the existence of ilmenite supposedly open German; most discussed element is now known as technetium.
Prout`s hypothesis checking, defined in the 1842-83 atomic weights of 29 elements. In 1866 he developed a method of separation of niobium and tantalum. In 1878 he opened the ytterbium oxide, and in 1880 - a rare earth element oxide is unknown, later named (1886) of gadolinium oxide (see lanthanides.).