400 Scientific Intelligence. 
anthanum and didymium from yttria and erbia by means of sulphate 
of potash, repeating the operation until the solution no longer exhibits 
i tria and 
_manner by repeated operations the two earths were finally separated, 
the equivalent of: yttrium being found to be 30°85, while that of erbium 
is . Efrbia, as obtained by igniting the oxalate or nitrate with access 
of air has a faint rose-red color, and does not fuse at a white heat, but glows 
with an intense green light. The salts of erbia are more or less bright 
erbium and didymium and show that the two contain no line m- 
mon and that there are no absorption bands from which the existence of 
terbium can be infe The errors of previous observers in this par- 
The solid substance when strongly ignited gives a spectrum 
bands which in the case of erbia are so intense that they may be used 
