DYEING 173 



2. Ked with blue produces purple, violet, lilac, pigeon's neck, mallow, peach- 

 blossom, bku de rot, lint-blossom, amaranth, &c. 



Thus a Prussian blue dyed over a safflower red, or vice versd, will produce any of 

 these tints by varying the depth of the red and blue according to the shade required ; 

 but the same shades can be produced direct by logwood and an aluminous or tin 

 mordant ; the stuff being steeped in sumach liquor previously to applying the tin 

 mordant produces the reddish or purple tint when such is required. 



3. Ked with black ; brown, chocolate, maroon, &c. These tints are produced by 

 various processes. To dye a deep orange by annotto liquor, and then form over it a 

 black by sumach and sulphate of iron, gives a brown ; or dye the stuff first a rich 

 yellow by quercitron and a tin mordant, and then over the yellow produce a purple by 

 passing it through logwood ; chocolates are thus produced. A little brazil-wood with 

 the logwood gives more of the red element. When maroon is required, the red is 

 made to prevail, and so by a judicious mixture, these various tints are produced. 

 Brown, especially upon cotton fibre, is more often produced direct by means of catechu. 

 Steep the stuff in a hot solution of catechu, in which the gummy principle has been 

 destroyed by the addition of a salt of copper ; then pass through a solution of bichro- 

 mate of potash at boiling heat, when a rich brown is obtained. 



4. Yellow with blue ; green of a great variety of shades ; such as nascent green, gay 

 green, grass green, spring green, laurel green, sea green, celadon green, parrot green, 

 cabbage green, apple green, duck green, &c. 



Green is essentially a mixed dye, and produced by dyeing a blue over a yellow or 

 a yellow over a blue. In almost all cases the blue is dyed first, and then the yellow, 

 and according to the depth of each or any of these are the various tints of green 

 produced. With silk and wool, one kind of green dye may be produced simul- 

 taneously by putting sulphate of indigo into the yellow dye-bath, and then working 

 the previously-prepared or mordanted stuff in this. With cotton, an arsenite of 

 copper (Scheele's green) may be produced by working the stuff in a solution of 

 arsenite of potash or soda, and then in sulphate of copper, which produces a peculiar 

 tint of green. 



5. Mixtures of colours, three and three, and four and four, produce an indefinite 

 diversity of tints : thus, red, yellow, and blue form brown olives and greenish greys ; 

 in which the blue dye ought always to be first given, lest the indigo vat should be 

 soiled by other colours, or the other colours spoiled by the alkaline action on the vat. 

 Red, yellow, and grey (which is a gradation of black) give the dead-leaf tint, as well 

 as dark orange, snuff colour, &c. Eed, blue and grey give a vast variety of shades ; 

 as lead-grey, slate-grey, wood-pigeon grey, and other colours too numerous to specify. 



Care must be taken, however, in mixing these colours, to study the depth of the 

 tint required ; as, for instance, were we wishing to dye a slate-grey, and to proceed 

 first by dyeing a blue, then a red, with a little of the grey, we should produce, instead 

 of a slate grey, a purple or peach. The arrangement referred to, applies only to the 

 elements of the colours that enter into the composition of the various tints, so that a 

 slate-grey is a blue with a small portion of red, and a still smaller portion of the 

 black element, that produces the grey tint. Thus, dye the stuff first a deep sky-blue 

 by the vat, then by passing through a solution of sumach, with a small quantity of 

 logwood, brazilwood, copperas, and alum, grey will be produced. The brazilwood 

 gives the red tint, sumach and copperas the black tint, the logwood assisting in this, 

 and with the aid of the alum throwing in the puce or dove-neck hue ; and thus by the 

 variation of these hues by such arrangements, any of the grey tints can be produced. 

 See CALICO-PRINTING. 



ANILINE DYES. Dyeing and printing have undergone a considerable change through 

 the introduction of these dyes. The colours produced are more brilliant than formerly, 

 and. since the use of mordants has been almost dispensed with, the processes are very 

 much shorter. The styles and patterns have undergone a marked change. 



These dyes, however, have not yet supplanted the use of dyewoods and the other 

 colouring matters formerly in use. They are not so permanent, and at the same 

 time they are much more expensive. But continued improvements in the modes of 

 producing and applying these dyes will no doubt greatly advance and develope their 

 commercial importance. 



Reference to the article ANILINE, and also to CALICO-PRINTING, will show the sim- 

 plicity of the applications of these tinctorial substances, and the great variety of 

 decided colours and varying tints which are produced. 



We have not only the true aniline colours available for the use of the dyer and 

 calico-printer, but we have the Murexide Dyes, and others of an analogous descrip- 

 tion especially such as belong to the Picric Acid series which, by intercombination, 

 produce an almost infinite variety. 



In dyeing silk and wool with aniline colours no mordant is required. Solution 



