226 ILLINOIS STATE ACADEMY OF SCIENCE 



In summation then there are perhaps four metals of the 

 rare earths which will find commercial use : 



Cerium, which can be separated from the cerium group 

 with considerable ease and has already been prepared 

 and exhaustively studied.^ 



Cerium free misch metal, for which a demand will be 

 created in time. The element cerium having two stages 

 of oxidation is at times undesirable as a metal, and ce- 

 rium free misch metal would meet this difficulty. 



Cerium group metal, or misch metal which has found 

 considerable use in pyphoric alloys as deoxidizers. 



Yttrium group metal, slightly less electropositive in 

 character but having a much higher melting point. 



1. Hirsch. Trans. Am. Elec. Soc. 22, 57. 



