POTASSIUM NITRITO-HYDROXIMIDOSULPHATES. 217 



have recorded concerning the normal potassium hydroximido- 

 sulphate by itself. The double salt is exceedingly alkaline, its 

 alkalinity we estimated by means of decinormal acid and litmus. 



Like the previously described double salt it is but little 

 soluble in concentrated nitrite solution and freely soluble in water 

 which decomposes it into its constituent salts and also decom- 

 poses one of these, the normal hydroximidosulphate, into alkali 

 and crystals of the oj6 normal salt. When heated it decomposes 

 suddenly but gently and without fusing or scattering, and evolves 

 slight red fumes only. It was by this behaviour quite distin- 

 guishable from the 2/8 normal double salt and also from any 

 other hydroximidosulphate which, simple or combined with 

 nitrite, contained less than its K; to S^. By dissolving the 

 nitrito-2/3 normal hydroximidosulphate in a hot concentrated 

 solution of nitrite containing sufficient alkali the nitrito-normal 

 hydroximidosulphate can be readily obtained by cooling the 

 solution. 



Potassium nitrite and j^otassiimi Ö/6 normal hydroximidosul- 

 phate. — We have obtained three compounds of the 5/6 normal 

 salt with nitrite, one being TKNO., 2EIK5(NS20.)2, 30Ho. By 

 using an almost saturated solution of potassium nitrite con- 

 taining a little potassium hydroxide and dissolving in it by heat 

 the Ö/6 normal hydroximidosulphate there is obtained a compound 

 in minute fibrous crystals very lustrous when dry and decomposed 

 by water but recrystallisable from a saturated nitrite solution. 

 The same compound salt can be obtained also by dissolving the 

 nitrito-normal hydroximidosulphate in hot almost saturated solu- 

 tion of nitrite. 



Heated it proves to be mildly explosive. Its composition 

 approaches that indicated by the formula given above. For 



