46 



E. DIVERS AND T. HAGA. 



a little nitrons oxide alonir with the nitrogen. The nitrogen obtained 

 was about four-fifths of the total nitrogen of the salt, the rest remain- 

 ing in the residue as ammonia. So far as was asrertained — and 

 observation is difficult because of the explosive character of the salt — 

 the first jiortions of gas are richer in sul])hur dioxide than the last. 

 If this be reallv so, it ]ioints to the not im])robab]e intermediate 

 formation of some imidosnlphonate. 



From the facts observed, the decomposition of the disodiuni salt 

 seems to ^ arv between that expressed by — 



l^XaJlXS,(K-l^Xî«TISO,+ Xa,S(),+ 8(1,+ X, 



and that exjiressed by — 



SNaJIXS20~3Na,SO,+ r)Na,S,0;+ (NH,)oS,0,+ 8X,-l- SO,. 



ft will be seen tliat our ol)servations do not agree with tho.se 

 made l)y Claus as to the nature of the products of the decomposition 

 of oxiinidosulphonates liy heat. Fremy, Clans, and Raschig all state 

 that the five-sixths normal j)otassium salt gives red fumes when 

 lieated, and this also we cannot confirm ; whether in ci-ucible or in tube, 

 heated slowlv or quickly, it has never given us such fumes. Only 

 where reversion to nitrite and sulphite has taken place, as with lead 

 oximidosulphonate already noticed, does heat generate red fumes. 



n.r/(h's((]iil/fii. — Characteristic of the («imidosul])honates are, firstly, 

 tliat thcv do not reduce cop])er salts in presence of alkali, unless they 

 have been previously hydrolysed with acid ; secondly, that they yield 

 bv gentle oxidation Fremv's sulpliazilates, unstable salts, blue-violet in 

 solution, vellow and crystalline in the solid state. Traces of almcxst 

 anv oxidising" jigent capable of actin«'- in alkaline solution effect this 

 change in the alkaline salts, but oxidising agents of a basic character 

 act also on the neutral salts. Silver oxide and lead peroxide are the 

 best reagents lor detecting any oximidosul])hoiiate. These oxides 



