28 ART. 15— TAMEMASA HAGA. 



rendered insoluble some of the sulphate which should have dissolved 

 out through the hydrolysis of the aminedisulphonate simultaneously 

 precipitated. There seems, therefore, to be no reason for doubting the 

 quantitative accuracy of the equation given on page 6. 



An experiment was then tried to see whether closer results could 

 not be got by removing as much as possible of the aminedisulphonate 

 from the solution before precipitating the sulphate, first crystallising 

 out most of it from the nearly neutralised solution, and then removing 

 some of the remainder as the mercury-potassium salt, by digesting the 

 solution with mercuric oxide. This method, however, did not give 

 better results than the preceding. 



Reduction of Potassium Hydroxylaminetrisulphonate by the Zinc-copper 



Couple. The reduction of the trisulphonate was successfully effected 



by boiling its solution, (to which a few drops of solution of sodium 

 acetate had been added in order to protect the salt from hydrolysis) with 

 some zinc-copper couple. But in consequence of the necessity of boil- 

 ing the solution, hydrolysis of the aminedisulphonate is apt to set in. 

 Some aminedisulphonate, prepared by the sodium amalgam 

 method and another sample, prepared by the zinc-copper couple were 

 analysed with the following results : 



By sodium. By zinc-copper. Calc. 



Potassium 30-68 30-72 30*89 



Sulphur 25-09 24\S5 25*94 25-30 



Xitrogen 5*32 6*16 5-54 



Hydrolysis of a Hydroxylaminetrisulphonate. The complete 



hydrolysis of the hydroxylaminetrisulphonates is more difficult to 

 effect than that of any other of Fremy's salts. In the quantitative 

 analysis of the salts, it was found necessary to keep the acidified 

 solution for five hours at ISO — 200°. In the case of the potassium 

 salt, the mean percentage of sulphur then came out as 23.18 ; at 





