125 



.0158 



The first of these figures varies so widely from the others 

 that we are justified in rejecting it; in which case the mean 

 becomes 36.842, ± .0031. 



Siewert also made two analyses of silver anhydrochromate 

 by the following process. The salt, dried at 120°, was dis- 

 solved in nitric acid. The silver was then thrown down b}^ 

 hydrochloric acid, and, in the filtrate, chromium hydroxide 

 was precipitated by ammonia. Reduced to a uniform stan- 

 dard, we find from his results, corresponding to 100 parts of 

 AgCl, Ag2Cr207, as in the last column : 



.7866 grm. AgjCrjO^ gave .52202 AgCl and .2764 CrjO.,. 150.684 



1.0S9 " .72249 " •3840 " 150.729 



Mean, 150.706, zt .015 



Giving Berlin's single estimation equal weight with one 

 of these, and combining, we get a general mean of 150.816, 

 ± .074. 



Siewert 's percentages of Cr2 03 obtained from Ag^Ci\0>,, 

 are as follows, calculated from the above weighings. 



35^139 



35.262 



Mean, 35.2005, ± .0415 



Combining, as before, with Berlin's single result, giving 

 the latter equal weight with one of these, we have a general 

 mean of 35.236, ± .0335. 



For the ratio between silver chloride and chromic oxide, 

 Siewert's two analyses of the anhydrochromate come out as 

 follows. For 100 parts of AgCl we have of CrjOg : 



