102 K DIVERS AND T. HAGA. 



After oxygenous salts had come to be regarded as oxylic com- 

 pounds, sulphites were formulated as SO(OM),, in which M is symbol 

 for a univalent basic radical, and in accordance with this. E. Frankland 

 (Lecture Notes, 1866) expresed the sulphatic constitution of Pelouze's 

 salts by the formula, (NO) 2 :SO(OM) 2 , that is, he considered the sulphur 

 to become hexavalent by uniting with two nitric-oxide radicals, in 

 place of the atom of oxygen taken up by sulphites in oxidising. 

 Later on, as it became evident that inorganic sulphites were of one 

 class with organic sulphonates, and that sulphites, sulphates, and 

 thiosulphates are best formulated as M/SCVOM; MOSO./OM; and 

 MS"S0 2 *OM, respectively, it was seen that, by analogy, nitrososul- 

 phates had to be written, M(N 2 2 )S0 2 'OM, in which change of valency 

 is no longer exhibited. This view of the constitution of nitrososul- 

 phates and of their relation to sulphites was advanced, some ten years 

 ago, by us (J. Ch, Soc., 47, 203; see also 47, 218). 



The facts on which this view of the constitution of nitrososul- 

 phates, so far as it goes, rests, seem amply sufficient. First", there is 

 the production of the nitrososulphates in a way precisely analogous to 

 that of sulphates and thiosulphates from sulphites, namely, by leaving 

 a solution of a normal sulphite in contact with nitric oxide, oxygen, 

 or sulphur, as the case requires. Then comes the reversion of nitro- 

 sosulphates to nitric oxide and sulphites: not only do they, when 

 heated in the dry state, thus decompose (Pelouze) — wholly in the case 

 of silver-potassium nitrososulphate, partly in other cases (Hantzsch) — 

 but sodium nitrososulphate does so even in hot solution (see preceding 

 paper). For this behaviour is in full agreement with what has long 

 been known of the thiosulphates, notably of the calcium salt, which, 

 in the first place, is producible by digesting calcium sulphite and 

 sulphur with water, at a gentle heat, and, then, is decomposable into 

 these substances, by boiling its concentrated solution. Lastly, sodium 



