NITROGEN. 



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 : 



Unfiised. 

 157-492 



Mean, 



157 

 157 

 157 

 157 

 157 

 157 



157 



510 

 485 

 476 

 478 



471 



488 



4857 



Fused. 



157.474 

 157-481 

 157.477 

 157-471 

 157-470 

 157-463 

 157-469 



Mean, 157.472 



General mean, 157.474, zt .0014 



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



Unfused. 

 157.4964 

 157.4940 



Fused. 

 157.488 



157.480 



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 i)latinum dish. The results obtained, reduced 

 to vacuum weights, were as follows : 



.31202 AgNOg gave .19812 Ag. 



.47832 

 .56742 

 .57728 

 .69409 

 .86367 

 .86811 

 .93716 



1. 06170 



i.ic 



.30370 

 .36030 



.36655 

 .44075 

 .54843 

 .55130 

 .59508 

 .67412 

 .76104 



Ratio, 157.490 



" 157.498 



" 157.485 



" 157.490 



" 157-479 



" 157.479 



" 157466 



" 157-485 



" 157-494 



" 157-477 



Mean, 157.484, ± .0020 



* Journ. Amer. Cheni. Soc, iS, 995. iS 



