118 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 54 



Vnfused. 

 157.492 

 157.510 

 157.485 

 157.476 

 157.478 

 157.471 

 157.488 



Fused. 

 157.474 

 157.481 

 157.477 

 157.471 

 157.470 

 157.463 

 157.469 



Mean, 157.4857 Mean, 157.472 



General mean, 157.474, ± .0014 



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

 Unfiised. Fused. 



157.4964 

 157.4940 



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 crystalline 

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

 silver nitrate, mixed with an excess of pure potassium cyanide solution, 

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

 to vacuum weights, were as follows : 



.0020 



The most thorough and recent investigation of this ratio is that by 

 Eicliards and Forbes." They effected the synthesis of the nitrate from 

 the purest silver, tlie nitrate having been fused and tested for sucli 



' Journ. Amer. Chem. Soc, 18, 995. 1896. 



- Publ. Carnegie Inst., Washington, No. 69, p. 47. 1907. 



