SODIUM OR POTASSIUM : EDWARD DIVERS. 55 



])y heat is probably into silver, nitrogen, and nitric peroxide. 

 I had of course seen in my early work, the production of red 

 fumes but had attributed tliis to the nitric oxide meeting the 

 air, and to the decomposition at a higher temperature of the 

 silver nitrate which had been formed. The further study of the 

 decomposition which I have made has proved that always there 

 are produced metallic silver, silver nitrate, nitric peroxide, nitric 

 oxide, nitrogen, and possibly a trace of nitrite. 



Having assured myself that nitric j^d'Oxit^^c"» ^s well as 

 nitric oxide, is evolved by silver hyponitrite wdien heated, I 

 exposed some to heat in a rapid current of carbon dioxide in 

 order to sweep away as fast as I could, the nitric peroxide that 

 was i^rodueod. For the production of nitric peroxide may suf- 

 ficiently account for that of silver nitrate secondarily. The 

 nitric peroxide and the metallic silver should give the nitrate 

 (Divers and Shimidzu, J, Ch, Soc, 1885, 47, 630) but it seems 

 improbable that these two substances being produced would 

 then immediately interact at the same temperature. There is 

 however, no reason why the nitric peroxide of the decomposed 

 part of the salt should not act upon the undecomposed part of 

 it and thus produce nitrate, such interaction readily taking- 

 place. My experiment recorded above was instituted to see 

 whether I could not almost prevent the formation of nitrate. 

 The attempt failed, for I found as much as ^ of the total 

 silver as silver nitrate in the residue. But this result does not 

 disprove that the nitrate really is formed in the way suggested. 



The nature and composition of the gaseous products were 

 ascertained by heating the salt in a vacuum. The quantity of 

 salt taken was in each experiment so proportioned to the capa- 

 sity of the little flask or bulb in which it was heated as that 



