Used with
permission of Maiken Naylor, University at Buffalo, Buffalo, NY, USA,
http://ublib.buffalo.edu/libraries/units/sel/exhibits/stamps
Johan Gadolin (1760-1852) was a Finnish chemist who in the late 18th century experimented with a mineral from Ytterby, Sweden, which contained new, uncommon oxides, or "earths." Over the next century other investigators were able to identify more than a dozen unknown elements contained in this rare earth, which were called lanthanides. Lecoq de Boisbaudran, himself the discoverer of gallium, named one of the rare earths to honor Gadolin: this was gadolinium.