557 



Mean, 48. 503, ± .0029 



Hence Yt = 88.449. 



The yttria studied by Jones* had been purified by Rowhmd's method^ 

 that is, by precipitation with potassium ferrocyanide— and certainly con- 

 tained less than one-half of one per cent, of other rare earths as possible 

 impurities. Two series of determinations were made — one by ignition of ^ 

 the sulphate, the other by its synthesis. The results were as follows, with 

 the usual percentage column added : 



Flni Series. Syntheses. 



* Amer. Cheni. Journ., 17, 154. 1895. 



