CERIUM. 



341 



necessary precautions, and the data obtained, reduced to a vacuum, were 

 as follows : 



Ce,(_SO,\. 

 2.16769 

 2.43030 

 2.07820 

 2.21206 

 1.28448 

 I -95 540 

 2.46486 

 2.04181 

 2.17714 

 2.09138 

 2.21401 

 2.44947 

 2.22977 

 2.7J662 

 2.62614 

 1.67544 



1.57655 

 2.72882 

 2.10455 

 2.10735 



2-43557 

 3.01369 



4.97694 



CeO.,. Percent. CeO.,. 



.31296 60.5693 



.47205 60.5707 



.25S60 60.5620 



.33989 60.5721 



.77845 60.6043 



.18436 60.56S7 



.49290 60.5673 



•23733 60.5997 



.31878 60.5739 



.26654 60.5605 



.34139 60.5863 



.48367 60.5711 



•35073 60.5771 



.65699 60.54S6 



.59050 60.5642 



.01470 60.5632 



.95540 60.6007 



.65256 60.5600 



.27476 60.5716 



.27698 60.5965 



.47517 60.5692 



.82524 60.5649 



.0137^ 60.5537 



Mean, 60 5729, ih .0021 



This mean completely outweighs the work done by Wolf and Wing, 

 so that upon combination the latter ])ractically vanish, ^\'ing's mean is 

 arbitrarily given equal weight with Wolf's, and the combination is as 

 follows : 



Wolf. 60.366, ± .030S 



Wing 60. 244, zb .0308 



Brauner 60.5729, ± .0021 



General mean 60.566, zt .0021 



In 189-5 several papers upon the cerite earths were published by Schutz- 

 enberger.* In the first of these a single determination of atomic weight 

 is given. Pure CeO,, of a yellowish white color, was converted into sul- 

 phate, which was dried in a current of dry air at 440°. This salt, dis- 

 solved in water, was poured into a hot solution of caustic soda, made 

 from sodium, and, after filtration and washing, the filtrate, acidulated 

 with hydrochloric acid, was precipitated with barium chloride. The 

 trace of sulphuric acid retained by the cerium hydroxide was recovered 

 by re-solution and a second precipitation, and added to the main amount. 



* Compt. Rend., 120, pp. 663, 962, and 1143. 1S95. 



