6 ART. 1. — E. DIVERS AND M. OGAWA : 



Ba(N 2 H 3 S 2 3 ) 2 , 20H 2 . It is soluble in water and its solution 

 behaves as that of an imidosulphite, being precipitable by baryta 

 (N 2 H 4 S 2 3 salts are not), and besides at once gives off ammonia 

 when moistened with potassium or barium hydroxide solution. 



The treatment of the orange mass of decomposed ammonium 

 amidosulphite with 95 per cent, spirit, as a preliminary to dis- 

 solving out the main quantity of imidosulphite with 90 per cent. 

 spirit, yields yellow alcoholic solutions which on evaporation in the 

 desiccator deposit crystals which are short thick prisms almost 

 cubical in appearance and about 2 mm. across. They are thus 

 quite unlike the minute micaceous needles of ammonium imido- 

 sulphite. They are yellow but the colour is adventitious. They 

 can be purified and rendered white by putting them into 95 

 per cent, spirit and then almost saturating this with ammonia 

 while the containing flask is kept immersed in cold water. In 

 this alcoholic ammonia they are very sensibly soluble. The solu- 

 tion is decanted and the treatment repeated until only a small 

 quantity of white powdery salt remains, principally imidosulphite 

 The solutions left for a while in open flasks and then exposed in 

 the desiccator over sulphuric acid lose most of the ammonia, and 

 the crystals reform from the solution. Washed with alcohol they 

 are left quite colourless. The mother-liquors evaporated in the 

 desiccator yield crude yellow crystals again which can be recrys- 

 tallised from alcoholic ammonia as before. 



These crystals are recrystallisable without change and have 

 also been prepared by us in two successive winters, yet they give 

 analytical results which are closely concordant with the remark- 

 able empirical formula, 4NH 3 , 5S0 2 or N 4 H 12 S 5 0i () . 



