514 SMITHSONIAX MISCELLANEOUS COLLECTIONS VOL. 54 



Kolle ' studied anhydrous cerium sulphate, which he reduced by cal- 

 cination to CeO,. His figures are as follows : 



Ge„iSO^):,. ceo.,. Per cent. CeO^. 



1.84760 1.11648 G0.429 



1.16074 .70078 60.331 



1.53599 .92722 00.366 



.97196 .58661 60.353 



1.40374 .84760 60.384 



1.75492 1.05956 60.377 



1.53784 .92853 60.379 



1.64233 .99150 60.372 



Mean, 60.374, ± .0067 



Hence Ce = 138.80. an unusually low and improbable value. 



The very careful investigation by Brauner and Batek" involved the 

 study of two cerium salts, the sulphate and the oxalate. The sulphate 

 was dehydrated at 440°, and then calcined to oxide. The figures given 

 in the next table represent a number of different samples of the salt, but 

 I have here combined the data into one series : 



Mean, 60.591, ± .0070 



Eeduced to a vacuum basis this becomes 60.584. 



Hence Ce = 140.30. 



Combining this series with others, we have 



Wolf 60.366, ± .0308 



Wing 60.244, ± .0308 



Brauner 60.5729, ± .0021 



WyroubofC and Verneuil 60.466, ± .0103 



Kolle 60.374, ± .0067 



Brauner and Batfek 60.584, ± .0070 



General mean 60.5528, ± .0019 



Wing's mean is here arbitrarily given equal weight with that of 

 Wolf, but both series practically vanish. 



^ BeitrSge ziir Kenntnis des Cers. Inaugural Dissertation. Ziirich. 1898. 

 -' Zeitsch. anorg. Chem., 34, 103. 1903. 



