NITKOGEN. 63 



parts of silver are given below in two columns, representing the two con- 

 ditions in which the salt was weighed. The general mean given at the 

 end I have deduced from the means of the two columns considered 

 separately : 



Unfused. Fused. 



IS7-492 157.474 



157-510 157.481 



157-485 157-477 



157.476 i57-47i 



157.478 157-47 



T57.47I 157.463 



157.488 157-469 



Mean, 157.4857 Mean, 157.472 



General mean, 157.474, .0014 



In the later series there are but two experiments, as follows : 



Unfused. Fused. 



157.4964 I57-488 



157.4940 i57-48o 



Mean, 157.4952 Mean, 157.484 



General mean, 157.486, .0003 



The reverse ratio, namely, the amount of silver obtainable from a 

 weighed quantity of nitrate, has been determined electrolytically by 

 Hardin.* The data obtained, however, are reducible to the same form 

 as in the preceding series, and all are properly combinable together. 

 Pure silver was dissolved in pure aqueous nitric acid, and the crystal- 

 line salt thus formed was dried, fused, and used for the determinations. 

 The silver nitrate, mixed with an excess of pure potassium cyanide solu- 

 tion, was electrolyzed in a platinum dish. The results obtained, reduced 

 to vacuum weights, were as follows : 



.31202 AgNO 3 gave .19812 Ag. Ratio, 157.490 



