4 ART. 1. E. DIVERS AND M. OGAWA : 



sulphite and ammonia. The salt is only moderately deliquescent 

 and, freshly prepared, is neutral to litmus.* It has a mild, un- 

 pleasant, sulphurous taste, which distinguishes it from the salt 

 occurring with it, more freely soluble than it in 95 per cent, 

 spirit, and already referred to. 



It is freely soluble in water but slowly decomposes into thio- 

 sulphate and amidosulphate. This change beginning at once, the 

 solution gives all the reactions of a thiosulphate. It goes on also 

 in presence of hydrochloric acid, which when hot hastens its com- 

 pletion. Barium thiosulphate has been prepared from the solution, 

 and amidosulphuric acid and ammonium amidosulphate also ob- 

 tained from it. Quantitative determinations of the sulphur, sulphur 

 dioxide, and amidosulphate, formed on boiling with hydrochloric 

 acid, gave results in agreement with the following equation : — 



2NH(S0 2 NH 4 ) 2 + 2HC1 = 2NH 2 S0 3 NH 4 4- 2NH 4 C1 + S0 2 + S, 

 in which the S0 2 and S represent decomposed thiosulphuric 

 anhydride. 



Potassium imidosulphite. — It has already been stated when 

 detailing the analysis of the ammonium salt that that salt yields just 

 two-thirds of its nitrogen as ammonia when boiled with potassium 

 hydroxide in aqueous solution. In accordance with this fact, it 

 has been found that potassium imidosulphite is obtained when to 

 the ammonium salt dissolved in 70 per cent, spirit, alcoholic 

 potash is added until the solution just renders red litmus paper 

 permanently blue on exposure to air. The salt soon separates as 

 minute micaceous crystals firmly adherent to the glass. After 



* As first obtained by us last year and then described, the salt had an acid reaction and 

 was exceedingly deliquescent. But as it showed a deficiency in ammonia (22.2 instead of 20.5 

 percent.), and as its potassium derivative was not acid, we indicated our expectation that 

 when obtained in a purer state the salt would prove to differ somewhat in properties from what 

 we had then found. 



