ON THE ACTION OF LIGHT UPON DYED COLOURS. 241 



Natural Colouring Matters. 

 Wool Book IV. 

 Mordant Colours. 1. Tesu (Cr.). 



„ 3. Young Fustic (Cr.). 



„ 15. Anthracine (Cr.). Composition not published. 



„ 2. Quercitron Bark (Al.). Bark of Quercus nigra. 



„ 3. Old Fustic (Al.). Wood of Moras tinctoria. 



„ G. Flavin (Al.). Quercetin prepared from Quercitron Bark. 



„ 7. Persian Berries (Al.). Fruit of Rhamnus saxatilis. 



„ 2. Persian Berries (Sn.). 



„ 3. Young Fustic (Sn.). 



4. Flavin (Sn.). 



„ 5. Quercitron I3ark (Sn.). 



„ 6. Old Fustic (Sn.). 



„ 7. Tesu (Sn.). 



Notes. — The fugitive character of Narcein as compared with Orange 

 II., of which it is merely the sodium bisulphite compound, is very pro- 

 nounced. The bright orange of Flavin with tin mordant changes rapidly 

 during the first exposing period to an olive-yellow, which may be regarded 

 as ' moderately fast.' A similar change is noticed in the case of Quercitron. 

 Bark and Old Fustic with the same mordant, the faded colour of the 

 latter being, however, very dull. 



With aluminium and tin mordants Anthracine gives bright but very 

 fugitive colours. 



Class III. Moderately Fast Colours. (Wool.) 



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

 period (July 1 to July 31, 1893), which becomes more pronounced at the 

 end of the third period (July 31 to August 26, 1893). A pale tint re- 

 mains at the end of the fourth ' period of exposure ' (August 26, 1893, to 

 February 19, 1894), 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 III. 



Acid Colours. 2. Orange GT. From toluidine and )3-naphthol-mono-sulphonic acid S. 

 S. and J. 41. 

 „ 4. *Mandarin GR. extra. From «-toluidine-mono-sulphonic acid and 



0-naphthol. S. and J. 78. 

 „ 5. *Orange II. From ^-sulphanilic acid and i3-naphthol. S. and 



J. 73. 

 „ 7. *Orange III. From wt-nitraniline and j8-naphthol-disulphonic 



acid R. S. and J. 33. 

 „ 10. Dimethylaniline Orange. From j;-sulphanilic acid and dimethyl- 



aniline. S. and J. 74. 

 „ 11. *Diphenylamine Orange. From ^>sulphanilic acid and diphenyl- 



amine. S. and J. 75. 

 „ 12. Tropscolin Y. From ^-sulphanilic acid and phenol. S. and J. 70. 



„ 15. *Metanil Yellow. From ?«-sulphanilic acid and diphenylamine. 



S. and J. 77. 

 „ 16. Resorcinol Yellow. From ^-sulphanilic acid and resorcinol. S. 



and J. 71. 

 „ 18. *Acid Yellow 00. Constitution not published. 



19. *Fast Yellow N. From jw-toluidine-o-sulphonic acid and 

 diphenylamine. S. and J. 79. 

 1894. R 



