DYEING. 



eight or ten minutes longer. The addi- 

 tion of the chalk heightens and brightens 

 the colour. 



To give a beautiful orange-yellow to 

 woollen stuffs, ten pounds of quercitron 

 bark tied up in a bag, for every hundred 

 pounds of stuff, are to be put into the 

 bath with hot water. At the end of six 

 or eight minutes, an equal weight of mu- 

 rio-sulphate of tin is to be added, and the 

 mixture to be well stirred for two or 

 three minutes. The cloth, first scoured, 

 and completely wetted, is then immer- 

 sed in the dyeing liquor, and briskly 

 turned for a few minutes ; by this pro- 

 cess the highest yellow may be produced 

 in less than fifteen minutes. 



High shades of yellow are given by 

 young fustic and nitro-muriate of tin, but 

 they are less permanent, less beautiful, 

 and more costly than those obtained from 

 ^he above bark. 



Of dyeing Silk yellow. 



To dye silk a plain yellow, in general, 

 weld alone is used. The silk* is first 

 scoured with soap, in the proportion of 

 twenty pounds of soap to the hundred of 

 silk, then alumed, and washed, 



The dyeing bath is prepared with two 

 pounds of weld to every pound of silk, 

 which, having boiled for fifteen minutes, 

 is to be passed into the vat through a 

 sieve or cloth. When the temperature 

 is as high as the hand can bear, the silk 

 is introduced, and turned, until it ac- 

 quires an uniform colour; during this 

 time the weld is to be boiled a second 

 time ia fresh water; one half of the 

 first bath is then taken out, and its 

 place supplied with a fresh decoction. 

 The temperature of the fresh bath may 

 be a little higher than that of the former, 

 but should not be too great, lest the co- 

 lour already fixed be dissolved. The 

 stuff is to be turned as before, and then 

 taken out of the bath. Soda is to be dis- 

 solved in a part of the second decoction, 

 and a larger or smaller quantity of the 

 solution is to be added to the bath, accor- 

 ding to the intensity of the shade want- 

 ed. The colour is examined by taking 

 out a skein and wringing it. 



To produce shades having more of a 

 gold colour, anotta is added in propor- 

 tion to the depth of the colour required. 



Lighter shades, such as pale lemon co- 

 lour, are obtained by previously whiten- 

 ing the silk, and regulating the propor- 

 tion of the ingredients of the bath by the 

 shade required. To give a yellow, with 



a green tinge, a little indigo is added to 

 the bath, if the silk has not been previ- 

 ously azured ; to prevent the greenish 

 shade being too deep, the silk should be 

 more slightly alumed than usual. 



Dr. Bancroft asserts that all the shades 

 of yellow can be given at a cheaper rate 

 by quercitron bark than by weld. To 

 dye with this bark, a quantity of it pow- 

 dered, and inclosed in a bag, in propor- 

 tion to the. shade wanted, from one to 

 two pounds for every pound of silk, is 

 put into the vat while the water is cold. 

 Heat is applied, and when the bath is ra- 

 ther more than blood warm, or of the 

 temperature 100, the silk, after being 

 first alumed, is immersed and dyed in the 

 usual way. A deeper shade may be giv- 

 en by adding a small quantity of chalk or 

 pearl-ashes towards the end of the ope- 

 ration. To produce a more lively yel- 

 low, a small portion of murio sulphate of 

 tin may be employed, but it should be 

 used cautiously, as it is apt to diminish 

 the lustre of the silk. 



To dye silk of an aurora or orange co- 

 lour, after having been properly scoured, 

 it may be immersed in an alkaline solu- 

 tion, of anotta, the strength of which is 

 to be regulated by the shade required. 

 The temperature of the bath should be 

 between that of tepid and boiling water. 

 When the desired shade is obtained, the 

 silk is to be twice washed and beetled, 

 to free it from the superfluous colouring 

 matter, which would injure the beauty 

 of the colour. When raw silk is to be 

 dyed, that which is naturally white should 

 be selected, and the bath should be near- 

 ly cold ; for otherwise the alkali, by dis- 

 solving the gum of the silk, destroys its 

 elasticity. Silk is dyed of an orange co- 

 lour by anotta, but if a redder shade be 

 wanted, it is procured by alum, vinegar, 

 or lemon juice. These colours are beau- 

 tiful, but do not possess permanency. 



Of dyeing Cotton and Linen yellow. 



In dyeing cotton or linen yellow, the 

 first operation is to scour the stuff with a 

 ley prepared from the ashes of green 

 wood ; it is then washed, dried, and alum- 

 ed with one fourth of its weight of alum ; 

 after twenty-four hours, it is taken out of 

 the alum liquor, and dried without being 

 washed. 4. weld bath is then prepared,' 

 by an infusion of a pound and a quarter 

 of weld for every pound of the stuff, and 

 in this it is dyed, by being turned and 

 wrought till it has acquired the proper 

 shade. It is then taken out of the bath, 



