34 Proceedings of the Royal Irish Academy. 



Hexasulphamide is insoluble in water, and in aqueous acids and alkalis, 

 but is soluble in organic solvents such as carbon disulphide, alcohol, arrd 

 chloroform. Chlorine oxidises it to N4S4, and alcoholic potash gives an 

 intense violet-red coloration, which disappears after a time, a persulphide 

 being formed. 



The large sulphur content of the compound is remarkable, and as the 

 melting point might suggest that the substance was a sample of impure 

 sulphur, the melting point of a mixture of the substance with sulphur was 

 taken and found to be 98°. The percentages of nitrogen and sulphur in the 

 compound were determined, and found to agree with the theoretical values 

 for hexasulphamide. The sulphur was oxidised to sulphate by careful 

 heating with a large excess of sodium peroxide in a nickel crucible, and 

 weighed as barium sulphate. The nitrogen was estimated by combustion 

 with copper oxide in an atmosphere of carbon dioxide according to Dumas' 

 method. Boiling with sodium hydroxide solution does not liberate all the 

 nitrogen as ammonia. 



0-1385 gram gave 0-9285 gram of BaSOj, whence S = 92-0 per cent. 

 0'1400 gram gave 0'9403 gram of BaSOa, whence S = 92-2 per cent. 

 0'359i gram gave 17'1 c.c. Nj at 12,755 mm., whence N = 6-5 per cent. 

 0-5020 gram gave 26-2 c.c. Nj at 11,755 mm., whence N = 6-4 per cent. 



SsNHs requires S = 92-3 per cent. ; N = 6-7 per cent. 



As has already been mentioned, hexasulphamide behaves in a similar 

 way to a mixture of nitrogen sulphide and sulphur, or the red nitrogen 

 sulphide (NjSs) on treatment with alcoholic potash : in all cases a violet-red 

 or amethyst coloration is developed, which disappears after some time. 

 No explanation has up to the present been advanced to account for this 

 colour development, but it is conceivable that it is connected with the 

 formation of a salt of a nitrogen-sulphur acid — 



SeNH, + KOH = SeNHK + H,0. 



Colour development in the case of hexasulphamide is not limited to the 

 action of potash, for the amethyst coloration is produced by alcoholic 

 solutions of the organic bases. The tint in these cases is, as a rule, not so 

 deep as that obtained with alcoholic solutions of potassium hydroxide. 

 If the solutions of the different bases are weak, some time elapses before 

 the colour develops, and the time is found to vary with the dilution of 

 the solution and the nature of the base. The figures in the following table 



