II. On radiant matter spectroscopy: Note on the Earth Yα

Abstract

Among the samarskite earths which concentrate towards the middle of the fractionations there is one (or a group) which presents in the radiant matter tube a well marked phosphorescent spectrum differing from those I have already described. The measurements of the bands and lines are given below:— The earth giving the above spectrum, when sufficiently purified, presents all the characteristics of the earth discovered by Marignac, and provisionally called by him Yα. Through the kindness of M. de Marignac I have been enabled to compare a specimen of Yα of his own preparation with the earth described above. The two earths agree in their chemical Characteristics, and their phosphorescent spectra are practically identical.