DYEING. 



To give scarlet the bright lively red, 

 culled Hre colour, a yellow tinge is com- 

 municated to the cloth by boiling fustic 

 in the first bath, or by adding a. little tur- 

 meric to the cochineal. A larger propor- 

 tion of the solution of tin also produces 

 this yellow shade, but it renders the cloth 

 harsh, and limits the action of the colour- 

 ing matter. 



I), Bancroft recommends a method of 

 dyt-i "g scarlet, in which a much smaller 

 portion of cochineal produces an equal 

 effect. He conceived scarlet, from his 

 experiments, to be a compound colour, 

 caused by about three-fourths of crimson 

 or rose colour, and one-fourth of pure 

 bright yellow. He therefore supposed, 

 that, when the natural crimson of the 

 cochineal is made scarlet, by the usual 

 process, a fourth of the colouring mat- 

 ter of the cochineal must be changed 

 from its natural crimson to a yellow co- 

 lour by the action of the solution of tin. 

 For this reason he introduced a bright 

 yellow dye into the bath with the cochi- 

 neal, and reduced the quantity of this 

 more expensive ingredient. He also 

 found that a mixture of two pounds of 

 sulphuric acid with about three pounds 

 of muriatic acid, poured on fourteen 

 ounces of granulated tin, with expo- 

 sure to heat, produced a solution of tin, 

 that had twice the effect of the common 

 nitro-muriatic solution, at less than a 

 third of 'the expense, and which raised 

 the colours more, without producing a 

 yellow shade. For the yellow dye, Dr. 

 Bancroft used quercitron bark. His pro- 

 cess for dyeing scarlet, by the use of this 

 substance, and the above preparation of 

 tin, is as follows : 



An hundred pounds of cloth are to be 

 put into a tin vessel, nearly filled with 

 water, in which about eight pounds of 

 the murio-sulphuric solution of tin have 

 been previously mixed. The liquor is 

 made to boi), and the cloth is turned 

 through it by the winch for a quarter of 

 an hour in the usual manner. The cloth 

 is then taken out, and four pounds of 

 cochineal, with two pounds and a half 

 of quercitron bark in powder, put into 

 the bath and well mixed. The cloth is 

 then returned into the liquor, which is 

 then made to boil, and the operation 

 is continued, as usual, till the colour 

 be duly raised, and the dyeing liquor 

 exhausted, which will usually happen 

 in about fifteen or twenty minutes; af- 

 ter which the cloth may be taken out, 

 :ind rinsed as usual. In this method, the 



labour and fuel necessary for the second 

 bath are saved; the operation is finished 

 in much less lime; all the tartar wiil be 

 saved, as well as two-thirds of the expense 

 of the solvent for the tin, and at least 

 one-fourth of the cochineal usually em- 

 ployed ; and the colour produced will not 

 be inferior, in any respect, to that dyed 

 with, so much more expense 'uul trouble 

 in the ordinary vvav ; and, moreover, looks 

 much better than it by candle light. 



A rose colour may be readily and 

 cheaply dyed by the above process, by 

 only omitting the quercitron bark. 



Crimson is produced either by dyeing 

 the wool this colour at once, or by first 

 dyeing it scarlet, and then changing ' he 

 shade to that required. To dye crimson 

 by a single process, a solution of two 

 ounces and a half of alum, and an ounce 

 and a half of tartar, are employed in the 

 boiling for every pound of the stuff", for 

 each of which also an ounce of cochineal 

 is to be afterwards used in dyeing it. 

 It is customary to employ solution of tin, 

 but in smaller proportion than for dyeing 

 scarlet. To render the crimson deeper, 

 and give it more bloom, archil and pot- 

 ash are frequently used, but this bloom is 

 extremely fugacious. 



To produce a crimson from a scarlet, 

 the alkalies, alum, and earthy salts are 

 used, all of which have this effect. Crim- 

 son is the natural colour of the cochineal, 

 and to produce it from a stuff' dyed scar- 

 let, the stuff' is boiled far an hour in a 

 solution of alum, the strength of which 

 is to be regulated by the depth of shade 

 required. 



Of dyeing Silk red. 



The red colour obtained from madder 

 does not possess sufficient brightness for 

 silk ; one of the best processes for its use 

 is the following of M. Guhh'che ; for every 

 pound of silk, four ounces of alum and 

 one of solution of tin are to be mixed 

 with water ; when the liquor has become 

 clear it is decanted, and the silk is soaked 

 in it for twelve hours, after which it is 

 immersed in a bath of half a pound of 

 madder to each pound of silk, softened 

 by boiling with an infusion of galls in 

 white wine. The bath is to be kept mo- 

 derately hot for an hour, and then made 

 to boil for two minutes. The silk is then 

 to be taken out, washed in a stream of 

 water, and dried in the sun. The colour 

 thus obtained is very permanent, 

 leaving out the galls it is clearer. 



