198 E. DIVERS AXD M. OGAWA : 



liolic solution, cooled and charged with ammonia, gives minute 

 scaly crystals in small quantity. This substance, dried in a 

 current of ammonia, has a composition expressed by (NH3)3S203, 

 nnd dried in the sulphuric-acid desiccator, that of (NH3)2S203. 

 These three substances all give the silver-nitrate reaction of the 

 aqueous solution of the whole residue, and on boiling with dilute 

 hydrochloric acid give very little sulphur and no sulphur dioxide. 

 At higher temperatures, whether dry or in solution, they yield 

 sulphur, sulphur dioxide, and sulphate. Two potassium deriva- 

 tives of these salts have also been prepared. Neither the crude 

 residue nor any of the above substances yields all its nitrogen as 

 ammonia when distilled with alkali, unless it has been first 

 heated with hydrochloric acid under pressure. 



From the mother-liquor of the above mentioned S2O3 salt a 

 substance was got which in composition and behaviour appeared 

 to be sulphamide a little impure. Neither sulphamide nor amido- 

 sulphate can be found in the fresh aqueous solution of the whole 

 residue, but, by heating the solid residue itself to a higher 

 temperature, imidosulphate is obtained in considerable quantity, 

 besides sulphur and sulphate, and imidosulphate is a known 

 product of first heating and then dissolving in w^ater, either 

 amidosulphate or sulphamide. A proof-spirit extract and also a 

 wood-spirit extract of the residue yield ammonium amidosulphate 

 on evaporation, no doubt generated by hydration. An aqueous 

 solution of the less heated residue, treated with excess of barium 

 acetate and filtered, gave barium thiosulphate in crystals, on 

 evaporating it over the water-bath. 



During the heating of ammonium amidosulphite at a tem- 

 perature of 30° to 35°, besides much ammonia, small quantities 

 of water and of sulphur dioxide are evolved, the former mainly 



