54 



THE QUANTITATIVE SYNTHESIS OF ARGENTIC NITRATE, ETC. 



of silver was used in syntheses 10, 11, and 12, and sample F in the 

 other three. 



The Synthesis of Argentic Nitrate. 



probable error of this average, computed from the results when car- 

 ried to the next decimal place, is only 0.0001, a wholly negligible quantity. 

 Hence repetition of the process was unnecessary. 



For this ratio just found to be 100.000 :157.480, Stas obtained an aver- 

 age of 100.000:157.475 from nine determinations, which ranged from 

 157.463 to 157.488. 



Better agreement than that exhibited by the above table could hardly 

 be desired or expected, as the greatest deviation corresponded to less 

 than 0.1 mg. in the weight of the argentic nitrate. This series demon- 

 strated that it is not necessary to use very large amounts of material 

 in order to attain a very high order of precision, if only the details of 

 experimentation are fittingly arranged. 



Satisfactory as this series of results appears to be, it is by no means 

 to be accepted without further question as representing the true weight 

 of argentic nitrate to be obtained from pure silver. Even in this fused 

 salt, prepared under such favorable conditions, several impurities might 

 exist; and because in each case the method of treatment was the same, 

 these impurities might be constant in amount and therefore not perceiv- 

 able in the results. Accordingly, attention was now directed to the search 

 for these impurities; and this part of the investigation was found to be 

 the most arduous and time-consuming part of it. The following section 

 discusses this matter. 



