ON COLORING. 55 



has a sufficiently strong affinity for the coloring matter and the 

 cloth, and a coloring matter which possesses the wished for color 

 in perfection, but we must procure a mordant and a coloring 

 matter which, when combined together, shall produce the wished 

 for color in perfection. 



The colors denominated by dyers simple, because they are 

 the foundation of all their other processes, are four, viz. blue, 

 yellow, red, and black. A few simple directions for dyeing 

 wool, silk and cotton of these colors will now be given. We 

 write for prudent and economical housewives, silk culturists, and 

 agricultural manufacturers, and the means within the reach of 

 such must therefore be kept continually in view, in all the oper- 

 ations recommended. 



BLUE. 



Indigo is the only substance that can be economically used in 

 families for coloring blue. The best or purest indigo is light, 

 easily powdered, tasteless, almost destitute of smell, and breaks 

 smoothly, that is, with smooth surfaces. Some will float on water, 

 and this is generally the purest. The color of indigo also varies. 

 There is the blue, the violet, and copper colored. Although 

 these may all contain nearly the same quantity of coloring mat- 

 ter, yet they are difierently valued, the blue selling 20 per cent, 

 higher than the violet, and from 40 to 80 per cent, more than 

 the copper colored. The blue is preferred by dyers for combi- 

 nation, or solution in sulphuric acid, and the copper colored for 

 the indigo vat, in which it is dissolved in a potash lye, aided by 

 bran, madder, or other vegetable products, in a state of ferment- 

 ation. Before indigo can be applied and fixed upon the fibre of 

 cloth, it must be dissolved in water. But it cannot be dissolved 

 in water in its blue state; it must be converted to a green or yel- 

 low color, and then it readily dissolves, is attracted by the fibres 

 of the cloth, becomes permanently combined with them, and on 

 being exposed to the air becomes again blue. In the solution of 

 the indigo, therefore, consists the whole art of coloring blue. 

 The following are among the most easy and simple methods 



