512 SMITHSONIAX MISCELLAXEOUS COLLECTIONS VOL. 54 



Mean, 60.5729, ± .0021 



Hence Ce = 140.22. 



In 1895 several pa})ers upon the cerite earths were published by Schutz- 

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

 is given. Pure CeOg, 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. 

 100 parts of Ce,( 804)3 gave 123.30 of BaSO^. This may be assigned 

 equal weight with one experiment in Marignac's series, giving the fol- 

 lowing combination : 



Hermann 123.92G, ± .238 



Marignac 122.40, ± .138 



Schutzenberger 123.30, ± .238 



General mean 122.958, ± .1139 



Schutzenberger, criticising Brauner's work, claims that the latter was. 

 aft'ected by a loss of oxygen during the calcination of the cerium dioxide. 



In his second and third papers Schutzenberger describes the results 

 obtained upon the fractional crystallization of cerium sulphate. Prepa- 

 rations were thus made yielding oxides of various colors — canary -yellow, 

 rose, yellowish-rose, reddish and brownish-red. These oxides, by syn- 

 thesis of sulphates, the barium-sulphate method, etc., gave varying values 

 for the atomic weight of cerium, ranging from 135.7 to 143.3. Schutzen- 

 berger therefore infers that cerium oxide from cerite contains small 

 quantities of another earth of lower molecular weight; l)ut the results as 

 given are not conclusive. The third paper is essentially a continuation 

 of the second, with reference to the didymiums.^ 



Schutzenberger's papers were promptly followed by one from Brauner,'* 

 who claimed priority in the matter of fractionation, and gave some new 



1 Compt. Rend. , 120, pp. 663, 962, and 1143. 18'J5. 



=> Similar results were also obtained by Boudouard (Conipt. Rend., 125, 772. 1897). The correct- 

 ness of these conclusions is questionable. 

 s Chem. News, 71, 283. 



