ON THE ACTION OF LIGHT UPON DIED COLOURS. 377 



the purplish colour produced soon fades, however, and at the end of a year 

 a pale grey remains. Acid magenta becomes duller but not bluer. 



The rhodamines, pyronin G, and aoridine red become yellower. 



Cloth red 3 Q extra and 8 B extra become distinctly yellower; 

 ponceau 2 S exti'a becomes much bluer. 



Cam-wood red is remarkable for becoming quite brown and appear- 

 ing, therefore, darker at the end of the first fading period. This colour 

 soon fades, however, and leaves at the end of a year a pale drab tint. 



Class III. Moderately Fast Colours. (Wool.) 

 The colours of this class show distinct fading at the end of the 

 second period (June 14 to July 21, 1892), which becomes more 

 pronounced at the end of the third period (July 21 to August 14, 1892). 

 A pale tint only remains at the end of the fourth period (August 14 

 to February 16, 1893), and at the end of a year's exposure the colour 

 has entirely faded, or, at most, mere traces of colour remain. 



Azo Colours. 

 Wool Book I. 



Acid Eeds. 3. Scarlet G. From xylidine and e-naphthol-di-sulphonic acid K. 



S. and J. 49. 

 J, 4. Scarlet B. 



,, 5. Brilliant Scarlet GG. From ?rt-sylidine and j3-naphthol-di-sulphonic 



acid E. S. and J. 50. 

 „ 7. Lake Scarlet GG. Same as 5. 



,) 10. Brilliant Scarlet G. Same as 3. 



„ 11. Scarlet GR. From xylidine and yS-naphthol-mono-sulphonic acid S. 



S. and J. 47. 

 „ 14. Lake Scarlet R. Same as 3. 



„ 15. Ponceau R. 



„ 17. Scarlet R. From ^- and «j-xylidine and )3-naphthol-di-sulphonic 



acid R. 

 „ 21. Scarlet 2 R. Same as 5. 



„ 22. Double Brilliant Scarlet 2 R. 



„ 23. Pyrotin Red 3 RO. From yS-naphthylamine-sulphonic acid D and 



a-naphthol-mono-sulphonic acid C. 

 „ 25. Persian Red. 



„ 27. Crocein Scarlet OXF. From naphthionic acid and ;8-naphthol-mono- 



sulphonic acid B. S. and J. 86. 

 „ 28. Ponceau 2 R. From amido-azo-benzene and )3-naphthol-mono-sul- 



phonic acid B and S. S. and J. 108. 

 „ 29. Cochineal Scarlet 2 R. From toluidine and o-naphthol-mono-sul- 



phonic acid C. S. and J. 40. 

 „ 31. Cochineal Scarlet 4 R. From xylidine and a-naphthol-mono-sulphonic 



acid C. S. and J. 45. 

 „ 32. Ponceau 3 R. From amido-ethyl-dimethyl-benzene and /3-naphthol-di- 



sulphonic acid R. S. and J. 51. 

 „ 33. Coccin BB. 



,, 34. Naphthol Scarlet. From naphthionic acid and j3-naphthol-sulphonic 



acid. 

 „ 37. Cochineal Scarlet R. 



„ 38. Anisol Red. From ortho-anisidine and jS-naphthol-mono-sulphonic 



acid S. S. and J. 54. 

 „ 39. Ponceau 4 R. From cumidine and /3-naphthol-di-sulphonic acid R. 



S. and J. 51. 

 „ 40. Azo-eosin. From ortho-anisidine and a-naphthol-mono-sulphonic acid 



NW. S. and J. 55. 

 41. Coccinin. From ortho-amido-phenetol and )8-naphthol-di-sulphonic 



acid R. S. and J. 41. 



