Iron Mordant containing Alum, 203 



MIXED MORDANTS. 



Alum and iron mordants can be mixed in all proportions, 

 and so produce numerous gradations in colour. In order 

 to form such colours properly, the following mordants 

 may be used : — j 



ALUM MORDANT CONTAINING IRON. 



Let 20 lbs. alum and 10 lbs. iron alum be dissolved in 

 160 lbs. of boiling water, and when the solution has some- 

 what cooled add 30 lbs. sugar of lead. Stir frequently and 

 allow it to clarify. This mordant remains permanent for 

 months. 



IRON MORDANT CONTAINING ALUM. 



Let 20 lbs. of iron alum, and 10 lbs. alum be dissolved 

 in 160 lbs. of boiling^ water, and when the solution has 

 somewhat cooled, add 30 lbs. sugar of lead. Stir it and 

 allow it to clarify. This mordant soon changes by the 

 precipitation of oxide of iron ; only a small stock of it, 

 therefore, should be kept : or in place of one half of the 

 water substitute vinegar. The mordanting of dark grounds 

 is performed as with alum and iron mordants. 



The drying must be quickly performed, as the iron 

 mordant readily separates from the alum mordant and runs 

 into the borders. Hence, these become mostly darker in 

 dyeing. This property can be exhibited easily, on a small 

 scale, by allowing a drop of the alum mordant containing 

 iron to fall upon a piece of calico, to dry slowly, and then 

 to dye it with tannin. The border appears almost black, 

 while the spot itself is dyed grayish yellow. 



The light colours or light grounds are formed with the 

 same mordant in the same manner : only that they are not 

 dried, but, after similar drying and pressing between the 

 rollers, they are immediately washed. The same mordants 

 may also be employed successively, instead of in the form 

 of mixture, to produce the different shades. 



After the cloth impregnated with the mordant, for pro- 

 ducing dark brown red, has been allowed to hang several 

 days, it should be passed through a hot cow-dung bath. 



The cloth prepared for light brown-red will be equally 

 dyed after rinsing, without the use of cow-dung. 



