of the oxides of Didymium and Erbium, etc. 



205 



solution contained in B removed ; the oxide was precipitated 

 as oxalate, filtered, and ignited to obtain the oxide and weighed. 



Didymium oxide. DL0 3 . 



It will be seen from these tables that, as before stated, the 

 most accurate results are obtained when the solutions are not too 

 highly concentrated. Therefore, if the solutions in the first 

 instance have their absorption bands wide and intense, they 

 should be diluted to a definite volume, and to such an extent 

 that the separate bands above mentioned are clear and well 

 defined. 



Finally, I desire to thank Professor Liveing for his kindness 

 now, as always, freely given. 



VOL. XII. PT. III. 



14 



