42 E. DIVERS AND T. HAGA. 



reversion, but in practice, in consequence doubtless of the traces of 

 alkaline salt purposely left in them as a guard against rapid hydro- 

 lysis, they do when kept dry develope a little sulphite before they 

 hydrolyse. The disodium salt, which is an anhydrous salt, may 

 however be kept for years in a desiccator \\ithout suliering sensible 

 reversion. In comparison with the others, the live-sixths normal 

 potassium salt and the disodium salt are the salts of their respective 

 metals best fitted to keep in stock for any considerable time. 



The dry lead salt reverts wdien heated. This salt is a basic or 

 hydroxy-salt, and when moderately heated is decomposed, thus : — 



(HO?b)3NS207 = HOPbNO, + 2PbSO:3 + HoO 



The residue if further heated evolves red fumes, and if moistened with 

 sulphuric or hydrochloric acid evolves much sulphur dioxide. 



Other clieritical projicrties of oxiniidü6ülj>ho)iates. 



Hydrolysis. — Tlie hydrolytic decomposition of oximidosulphonates 

 has been repeatedly referred to in this paper, and is besides a fact long- 

 known. Its almost inevitable occurrence in every alkali oximidosul- 

 phonate is all that needs further notice. When by circumstances or 

 by intention the salt is rendered acid, h3'drolysis always quickly 

 ensues. An alkaline salt when there is any water available, always 

 becomes acid in time by suffering reversion, and thus its hydrolysis is 

 brought about. 



In dilute solutions of oximidosulphonates acidified, hydrolysis 

 proceeds without complication, but in strong solutions, and when the 

 change is carried through, l)y heating, to hydroxy lamine sulphate, 

 some gas is produced, — nitrous oxide and nitrogen. In hydrolysing 

 for analytical purposes, this is manifested by pressure in the sealed tube, 

 and by a deficiency in the quantity of hydroxy lamine (cf. Raschig). 



