INTEKACTION BETWEEN ÖULPHITEÖ AND NITllITEÖ. 293 



This interaction is what, we believe, Raschig must iiuidver- 

 tently have got, when seeking to prepare Peloiize's !?alt (hyponi- 

 trososulphate) by the use of nitric oxide. The conditions are 

 favourable to the production of the nitrito-hydroxiinidosulphate 

 (this vol., p. 222). 



III. — c. Action of Sulphur Dioxide upon Normal Sulphite 



and Nitrite. 



It has been shown in this paper (sect. I. b) that the hydrox- 

 iniidosulphate which, from the first, accompanies the normal 

 sulphite as joint product of the action of sulphur dioxide upon 

 iilkali nitrite and hydroxide, keeps steadily to small proportions 

 to the sulphite until nearly all the hydroxide has been saturated. 

 After that point is passed and when, therefore, sulphur dioxide 

 is meeting a mixture of nitrite and normal sulphite, examination 

 of the solution, by the method already described, shows that, 

 along with a greater production of hydroximidosulphate than 

 before, there is pyrosulphite produced in no insignificant quantity. 

 This remarkable growth in the quantity of pyrosulphite, considered 

 along with the fact (sect. II. a) that it is itself active upon 

 nitrite proves that much of the sulphur dioxide goes altogether 

 to the normal sulphite. Only after the greater part of this salt 

 has been acidified to pyrosulphite is the sulphur dioxide active 

 in sulphonating the nitrite, whicli it tlien does by combining 

 with it in conjunction with the pyrosulphite, thus : — 



2KN02+KoSA + 2S02 + OH,=2K2HNS20;, the hydroximi- 

 dosulphate being produced in this way with much greater facility 

 than by the pyrosulphite alone because of its ^jroduction not 

 being accompanied here by the regeneration of normal sulphite 



