ytterbium

At a meeting of the Russian Chemical Society held October 20, 1881 (and reported in the Bulletin de la Société Chimique de Paris, for August, 1882), Mendelejeff [Dmitri Mendeleev], the distinguished author of the periodic law, remarked that only two of the recently announced elements—scandium and ytterbium—had been satisfactorily confirmed. These have been obtained in a pure state by [Lars Fredrik] Nilson, and neither of them has absorption spectra.