9 E. "DIVERS AND T. H Ar, A. 



its preparation, one just iJ-iven (p. lî') and the other now to follow 

 (p. 27). 



Oximidosiilphonates prepared by the iifie of siilplnir-dioxide. 



Jiitrodvctiiuu — F'remy's process for the nevtnti jjotassium salt is to 

 pass siilphnr dioxide into a snitably concentrated solution of potassium 

 nitrite and hydroxide, until the s:dt separates. Should the solution, 

 however, he sufficiently concentrated, the basic oximidosulphonate will 

 make its appearance instead, he found ; and with higVi concentratioji 

 the Aulphazafe, and occasionally tlie wetnsiilpliazate will first form. 

 Then water must be added, enough to dissolve up any of these salts, 

 and the passage of sulphur dioxide be continued until the neutral salt 

 begins to crystallise. 



Claus found Fremy's juvsci-iption too indefinite and uncertairj, 

 and therefore modified it, mainly so far as to employ equivalent 

 quantities of nitrite and hydroxide. He could <ret no ^uoh simple 

 succession of salts as Fremy had obtained, and he had ;d ways much 

 nitrile to de:ii with, a salt which giive no trouble to F'reniy. Keeping 

 the mixture cool during the entry of the sulphur dioxide, he got a 

 solution which, not immediately, as Fremy had found, but oidy on 

 standing, gave crystals of the neutral oximidosulphonate. Letting 

 the mixture grow hot by the action of the sulphur dioxide, crystals 

 wseparated, very much like Fremy's sulphazate, and these treated with 

 enough water left much insoluble nitrile and gave a solution wliich 

 slowly deposited crystals of the neutral oximide along with those of 

 the basic oximide. 



Raschig, in the specification of his patent, appends to the account 

 of the process he gives for the preparation of the neutral oximidosul- 

 phonate a statement to the effect tint this may also be obtained by 

 passing sulphur dioxide in excess into a solution of alkali nitrite and 



