233 



The color reappears on heating and disappears on cooling. With the exception of 

 acid magenta (A) (462) they are all absorbed by fuller's earth. 



I hi, iion/ ml. 



(1) Dye wool from acid bath only, do not dye unmordanted cotton in either bath. 

 Acid magenta (462), color absorbed by aluminum hydroxid. Dyed wool is decol- 



orized by hydrochloric acid, sulphuric acid, sodium hydroxid, or ammonium hydroxid. 

 Tannin reagent gives no precipitate. 



(2) Dyes wool and also unmordanted cotton most readily from a neutral bath. 

 Fuchsin (448), color not absorbed by aluminum hydroxid. Dyed wool turned red 



brown by hydrochloric acid or sulphuric acid. Tannin reagent gives a precipitate. 

 . I>ves wool yellow from neutral or alkaline bath. Does not dye unmordanted cot- 

 ten. Auranin (425). 



Dye wool green. 



Dye from acid bath: Guinea green B (A) (433) and acid green (434) do not dye rot ton. 



Dye from neutral or alkaline bath : Kthyl green (428) dyes unmordanted cotton 

 more readily than mahn-hite green. 



Malachite green (427 >. dyed \v..,,l i> blue u r rv-n. turned at tirst <_:ra>< rern by hydr..- 

 chlorir ai id <>r -ulphuric acid, then \ellow; mi dilution, blue 



I>ye wool violet from neutral or alkaline bath. 



Methyl v j..let (451), sodium hydroxid gives a brown precipitate and brown solution 

 Ethyl violet (453), sodium hydroxid gives a white precipitate, < lories.-* on warming 

 Either dyee unmordanted cotton ir-.m alkaline bath 



Dye* wool blue from acid bath. 



China blue (480), color absorbed by aluminum hydroxid Solution decolori/.-d 

 by sodium bisulphite reagent. Color does not readily return on heating, but d- 

 return on adding a drop of hydrochloric acid. Dyed wool de< >!.. ri/.-d by ammonium 

 hydr<>\id, turned reddish brown by sulphuric acid. 



COLORS or CLASS IV. 



Colors not reduced by stannous chlorid. Solution not de.-.-|,,n/e.| and . ..|..r not 

 completely precipitated by sodium hydr 



Dye wool red from neutral bath . 



Dyed wool is red orange to orange red : 



Eosin (512), color not absorbed by fuller's earth nor by aluminum hydroxid. \Vat-r 

 solution yellow to omnge with green fluoren em Ihdr.M h|,,rir ; ,<-jd ,, r sodium 

 bisulphite reagent gives an orange precipitate. 



Dye wool bluish red from neutral bath: 



(a) Color completely absorbed by fuller's earth. Sodium bisulphite reagent gives 

 no precipitate, but causes only a loss of fluorescence. 



Rhodamin G (502), water solution red violet with red fluorescence. 



Rhodamin B (504), water solution bluish red with orange brown fluorescence. 



(6) Color only partially absorbed by fuller's earth. Sodium bisulphite reagent 

 precipitates the color. 



Krythrosin (516), water solution cherry red. (Green's tables give no fluorescence. 

 A sample marked "Qrubler" gave green fluorescence.) Hydrochloric acid gives an 

 orange brown precipitate. Sodium bisulphite reagent gives an orange-red precipitate. 



Rose bengal (520), water solution cherry red. No fluorescence. Hydrochloric 

 acid gives a brown-red precipitate. Sodium bisulphite reagent a pink precipitate. 



Phloxin (521), water solution bluish red with green fluorescence. Hydrochloric 

 acid gives an orange precipitate. Sodium bisulphite a pink precipitate. 



