122 THE ATOMIC WEIGHTS. 



.0369 



Wildeiistein,* in 1853, also made barium chromate the 

 basis of his researches. A known weight of pure barium 

 chloride was precipitated by a neutral alkaline chromate, 

 and the precipitate allowed to settle until the supernatant 

 liquid was perfectly clear. The barium chromate was then 

 collected on a filter, washed with hot water, dried, gentl}' 

 ignited, and weighed. Here again arises the objection that 

 the precipitate may have retained traces of alkaline salts, 

 and again we find deduced an atomic weight which is too 

 high. One hundred parts BaCrO^ correspond to BaCl, as 



follows : 



81.87 81.57 



81. 8q 81.75 



81.61 81.66 



81.78 81.83 



81.52 81.66 



81.84 81.80 



81.85 81.66 

 81.70 81.85 

 81.68 81.57 



81.54 81.83 

 81.66 81.71 



81.55 81.63 

 81.81 81.56 



81.86 81.58 

 81.54 81.67 

 81.68 81.84 



Mean. 81.702, ± .014 



Next in order we have to consider two papers by Kessler, 

 who employed a peculiar volumetric method entirely his 

 own. In brief, he compared the oxidizing power of potas- 

 sium anhydrochromate with that of the chlorate, and from 



"•^ Journ. fiir Prakt. Chem., 59, 27. 



