THE REDUCTION OF N'lTROSOSULPHATES. -o L 



nitrososulphate is unstable and continuously decomposes in its «alkaline 

 solution, with evolution of gas. After treating nitrososulphate for 

 only 24 hours with sodium, the solution was mixed with excess of 

 barium nitrate and filtered from the precipitate produced. Silver 

 nitrate and some nitric acid added to the filtrate precipitated first a 

 little reduced silver and then silver hyponitrite equivalent to almost a 

 fifth of the total nitrogen of the nitrososulphate. 



Nitrous oxide and nitrogen. — No estimate has been attempted of the 

 nitrous oxide, but it is formed, certainly, in large quantity. It 

 appears to be generated along with amidosulphonic acid, as well as 

 with hyponitrite. Nitrogen probably accompanies it, since hydrazine 

 is produced. 



Sulphate. — There being so much sulphite produced we expected 

 difficulty in determining whether sulphate was a direct product of 

 the reduction of the nitrososulphate, or only the result of incidental 

 oxidation of sulphite by the air. But we experienced none. When 

 the water present is not more than 3 parts to 1 of nitrososulphate, an- 

 hydrous sodium sulphate precipitates out before the solution has been 

 removed from the amalgam and come in contact with air. We have got, 

 in this way, 4 grams of anhydrous sodium sulphate (containing only a 

 very little sulphite) from 50 grams of potassium nitrososulphate. Not 

 much sulphate then remained in solution, for the barium precipitate 

 from it largely dissolved in hydrochloric acid. It must be remember- 

 ed that in concentrated solutions of alkali, salts are very little soluble. 

 It would seem safe to say that as much as one-seventh of the sulphur 

 is yielded by the reduction as sulphate. The quantitative determi- 

 nation of the sulphate produced by the reduction is not only interfered 

 with by the presence of sulphite, but by that of much amidosulphonate ; 

 for this greatly retards, if it does not even prevent, precipitation of 

 barium sulphate and sulphite, unless excess of barium nitrate is used, 



