12 AET. 15,— TAMEMASA HAGA. 



should therefore be kept warm up to this point. When it has 

 remained some hours in an ice-box, almost the whole of the peroxyl- 

 aminesulphonate will have separated as a crust of minute orange 

 yellow needles. These can be recrystallised, but not without material 

 loss from hot water made slightly alkaline with potassium hydroxide. 

 When, as appears to have been the case with Fremy, much hydroxy 1- 

 aminedisulphonate has been left unoxidised, some of this will be found 

 with the peroxylaminesulphonate, from which it can hardly be wholly 

 separated by recrystallisation, its crystals remaining coloured by the 

 peroxylaminesulphonate, as observed by Hantzsch and Semple. 



Any close determination of the yield cannot be made directly, 

 since the salt can rarely even be roughly weighed before decomposition 

 sets in. Its amount has, therefore, to be estimated by letting it 

 decompose, igniting the residue with ammonium carbonate, and 

 weighing the potassium sulphate. In this way the yield of separated 

 salt was found to be a very little over three-fourths of the calculated 

 quantity, when silver oxide was used ; and a little less than two- 

 thirds when lead peroxide was taken. But by indirect means, the 

 amount of the salt actually produced can be shown to be much 

 higher than this. As already mentioned (p. 5), the exhaustive 

 oxidation by lead peroxide of a hot solution of hydroxylaminedisul- 

 phonate has given nearly 88 per cent, of the calculated quantity of 

 hydroxylaminetrisulphonate, a fact which signifies that at least as 

 much peroxylaminesulphonate as is equivalent to this percentage of 

 the total sulphur must have been formed, since its production is 

 intermediate to that of the hydroxylaminetrisulphonate. 



Potassium peroxylaminesulphonate is very unstable in water and 

 very little soluble in the cold. In N/J 0-solution of potassium 

 hydroxide, which fairly represents its usual mother liquor, it is more 

 stable, but still less soluble; 100 parts at 3° dissolve only 0.62 part 





