P3R0XYXA.MIXESULPH0NA VE3 AND II V n:;o\ y i,.\ m | \ i: PEISULPH >N" Vl'Ks. [g 



ed Claus's statements and also states thai the solid sail or Its 

 solution, also decomposes in this way even when left i.i contacl 

 with alkali. He also adds thai its solution when acidified is 

 decolorised in a few minutes, whilst in presence oi alkali it can in 

 some cases be heated to boiling without change. All these statements 

 by Claus and Raschig require to be modified in order thai they 

 may accurately describe the behaviour of the salt, and even then they 

 fail to indicate the primary change which the decomposing salt 

 undergoes. Thus, the acid sulphate produced is seldom equal to one- 

 fourth of the total sulphur, although it may be so, as twice found by 

 Claus, and indeed also in the present investigation, but only when 

 the salt had been used with too small a quantity of water to dissolve 

 it all on warming. Owing to this fact, only a part of the nitrogen, 

 which does not become hydroxy laminetrisulphonate, appears as nitrous 

 oxide, along with a small amount of free nitrogen. 



Solid potassium peroxylaminesulphonate is too unstable when 

 dry and free from alkali, to exist many minutes without rapidly and 

 almost explosively decomposing. In this decomposition, slight white 

 fumes of ammonium salt (probably pyrosulphite and pyrosulphate), 

 nitrogen and nitrous oxide, and a small quantity of sulphur dioxide 

 are given off, whilst the residue, when the mass of the salt has been 

 at all considerable, gets very hot (above 300° ?) and melts. This 

 residue consists of potassium sulphate (principally pyrosulphate) with 

 a very little ammonium salt. Sometimes a trace of aminemonosul- 

 phonate can be detected by the mercuric nitrate test ; also a trace of 

 hydroxylamine (or other substance reducing alkaline cupric solution), 

 but none of the other sulphonates, the temperature having been too 

 high to leave these substances undecomposed. 



The true products of the spontaneous decomposition of a 

 peroxylaminesulphonate are only found (in company with small 



