90 Proceedings of the Royal Irish Academy. 



acid was slowly added to a solution of "E-salt," which was prepared by 

 dissolving 40 grams of " E-salt " in 400 c.cs. of water, adding 10 grams of 

 caustic soda, with 5 grams of sodium carbonate, and cooling to 15° C. During 

 the addition the whole was stirred mechanically, and the stirring was continued 

 for five hours afterwards. Next day the colouring matter was heated to 

 80° C, and the solution saturated with common salt, when the colouring 

 matter was precipitated and filtered. It was purified by dissolving in hot 

 water, filtering, and cooling. The compound separated easily on cooling the 

 solution, and was filtered and dried. 



•2o44 substance gave 97 c.cs. moist nitrogen at 16° C. and 769 mm. P., 



corresponding to N = 4 - 80, 

 CnHuX.i >..s X;i. requires X = 4-79. 



The compound when pure is a reddish-blue powder, which dissolves in 

 water to a deep-red solution, and dyes cotton directly a violet red. 



6. Coupling of 1- •Sulp/ume-Disulphonic A<itl with "G-Acid" 



(fi-X"]ihtlwl-. phonic Arii/). 



x. OH BO,Nb SOtNa OH SOiN« 



I I 



«_/~\ /~\_N - v_/ \ 



" \_/ \_/ M " * \_/ 



/ S— SOiM ^SO,/ m,\ u _/ \ 



Etenridine-sulphone-disulphonic acid (20.3 grams) was dissolved in 150 c.cs. 

 of water and tetrazotised. The tetrazo solution was slowly added to the 

 "G-salt" solution whirl, W a.- prcpari-d 1 • v dissolving 40 grams of "G-salt" in 

 400 c.cs. of water, adding 10 grams of caustic soda, with 5 grams of sodium 

 carbonate, and cooling to 1 5 < !. 1 taring the addition the mixture was stirred 

 mechanically, and the stirring was continued for five hours afterwards. After 

 standing overnight the mixture was heated to 80° C, and the colour pre- 

 cipitated by saturation with common salt. The colouring matter was filtered 

 and dried. The compound was purified by heating with dilute alcohol and 

 altering, when it separated out on cooling. It is a reddish amorphous 

 powder, soluble in water to a deep-red solution, and acts on cotton as a direct 

 dye, giving a pink shade. 



•2420 substance gave 10- ."• c.cs. moist nitrogen at 16°C. and 768 mm. P., 

 corresponding to X 5'0 

 C„H M N.O M S 7 Na, requires N = 479. 



