DYEING. 195 



Greens are formed of blues and yellows. Wool 

 is dyed green by dyeing it first blue of a depth of 

 shade sufficient for the required kind of green. It 

 is then washed and boiled in a bath of weld and 

 tartar, or any of the processes used for dyeing blue 

 and yellow may be used. Various shades will be 

 given by different proportions of the dyeing ma- 

 terials. The green called Saxon green is obtained 

 by solutions of indigo in sulphuric acid, sometimes 

 quercitron bark is used. Another process for 

 Saxon green is by the quercitron bark, and then a 

 bath of the murio-sulphate of tin and alum with 

 sulphate of indigo. 



Purples, violets, &c. All the shades of these 

 colours are formed of blue and red. Sometimes 

 the cloth is dyed blue and then scarlet, and some- 

 times cochineal is mixed with sulphate of indigo, 

 artd the purple dyed at once. Silk is dyed first by 

 cochineal and afterwards by indigo. Cotton and 

 linen are dyed blue* then galled, and boiled in 

 logwood. 



Orange colours are produced by mixtures of 

 yellow and red* Wool is first dyed scarlet and 

 then yellow. 



Olive is blue combined \vith red and yellow. 



Cinnamon colour is given to wool by dyeing it 

 first with madder, then yellow. Silk is dyed the 

 same colour by logwood, Brazil-wood, and fustic. 

 Cotton and linen receive a cinnamon colour by 

 weld and madder. 



Brown is given to cloth by quercitron bark, or 

 by walnut peels. 



When walnut peels, or the green covering of the 

 walnut, are first separated, they are white internally, 

 but soon assume a brown or even a black colour 

 on exposure to the air. .They readily give up their 



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