CHROMIUM. 



121 



results were obtained quite near those of Berlin. Both of 

 these series are discussed together, neither having a remark- 

 able value : 



grm. alum gave .213 grm. Cr203. 16.155 percent. ] 



'•3185 

 .7987 



1. 0185 

 1.0206 



.8765 



.76S0 



1.6720 



.5410 



1.2010 

 I. 0010 



•7715 



1-374 



.0125 



The determinations made by Lefort* are even less valu- 

 able than those by Moberg. This chemist started out from 

 pure barium chromate, which, to thoroughly free it from 

 moisture, had been dried for several hours at 250°. The 

 chromate was dissolved in pure nitric acid, the barium 

 thrown down by sulphuric acid, and the precipitate collected 

 upon a filter, dried, ignited, and weighed in the usual man- 

 ner. The natural objection to the process is that traces of 

 chromium may be carried down with the sulphate, thus in- 

 creasing its weight. In fact, Lefort's results are somewhat 

 too high. Calculated from his weighings, 100 parts of 

 BaS04 correspond to the amounts of BaCr04 given in the 

 third column : 



1. 2615 grm. BaCrO^ gave 1. 1555 grm. BaSO^. 



1-5895 

 2-3255 

 3.0390 

 2.3480 

 1.4230 



I-I975 

 3-4580 

 2.0130 



1.4580 

 2.1340 



2.7855 

 2.1590 

 1.3060 

 1.1005 

 3.1690 

 1.S430 



109.174 

 109.019 

 108.974 

 109.101 

 108.754 

 108.708 

 108.814 

 109.119 

 109.224 



* Journ. fur Prakt. Chem., 51, 261. 1850. 



