OXIMIDOSULPHONATES OR S ULPH AZOTATES. 



19 



The saine investigator records tlie preparation, from sulphite, of 

 a potassiimi-sodiuin oxiniidosulphonate haAing- tlie basicity of Fremy's 

 basic potassium siilphazotate. Having on one <3ccasion poured com- 

 mercial soluti(jn of sodium bisulphite upon cold sodium nitrite he 

 found the mixture become boiling hot, and by addition of nmch potas- 

 sium chloride to yield nmch potassium -sodium nitrilosulphonate. 

 Then, during the twenty four hours following, the mother-liquor 

 deposited the new salt togetlier with some i)otassium nitrilosulphonate. 

 We have not been able to confirm his ex[)erience. The potassium- 

 sodium salts we can get, but according tu om- own observation, the 

 addition of alkali hydroxide, of which he says nothing, is requisite to 

 iorm an alkaline oxiniidosulphonate. And from Raschig's own sound 

 criticism (op. cit., p. :i'J'J) of Claus's method of getting the alkaline 

 potassium salt, it might be supposed that he too believed in this neces- 

 sity of adding hydroxide in order to form any basic oximide. 



Préparation of the neutral potassium oximidosulphouatc j'non metasul- 

 phite. — To prepare the potassium oxiniidosulphonate by using meta- 

 sulphite we ourselves work from the first with potassium salts. The 

 solutions of potassium nitrite and metasulphite are used w4th ice float- 

 ing in them, the mixture is kept in ice for a day or more, and the ice- 

 cold mother-liquor is then drained off from the crystals which will 

 have formed. To allow, as Raschig would, as we understand from 

 abstracts of the specification of his patent, the temperature to rise even 

 up to 40°, greatly interferes, and gives such a result as Claus obiain- 

 ed, — very much nitrile and very little oximide. Some nitrile forms 

 even in the ice-cold mixture and has to be washed away fn^ni the 

 oximide crystals ; and wlien the mother-liquor is afterwards allowed lo 

 acquire the common temperature it produces and deposits more nitrile. 

 The ]jroportion of tlie quantities of the salts to be taken is some- 

 what more than that of three molecules of metasulphite to two 



