DYEING OF SILKS. —The operations connected with the dyeing of silk are similar to those already sketched out, but a more thorough scouring of the raw material requires to be made, so as to remove all the gum and wax belonging naturally to the fiber.
30. Black is obtained by working the silken material in copperas (sulphate of iron), then in logwood containing some chamber liquid, and repeating the treatment with cop peras and logwood till the requisite shade is procured. A little nitrate of iron tends to give a more full, deep black; and alum and white soap are also used with advantage. Acetate of copper is occasionally used.
31. a blue as at 12, and then proceed as at 30.
32. Brown.—Obtain an orange by immersion in a solution of annotto, then treat with copperas; and introduce into a bath of fustic, logwood, archil, and a little alum. If a more yellow tint is required, add more fustic; redness is obtained by adding peach wood, and blueness by the addition of logwood.
33. Reds are obtained from peaehwood and fustic, and thereafter red spirits. Annotto
is used in getting up the scarlet shades, and coenineal and safflower in the more expen sive red dyes. Rubies and maroons require cudbear.
34. Pink—from safflower, associated with sulphuric acid and cream of tartar. • 35. Orange and Yellow—by treating the goods with more or less strong solutions of annotto, associated with alum and white soap.
36. Blue—from salts of iron and yellow prussiate of potash; or from solutions of sulphate of indigo, assisted with a little alum.
37. Green—from steeping in decoctions of fustic and sulphate of indigo, along with a little alum. The darker shades have copperas added and logwood.
38. li•ench and Pearl White.—Work the silk in a lather of white soap, to which archil or cudbear has been added, to give the required shade.
39. Drab—from decoctions of sumach, fustic, logwood, and more or less copperas, according to the depth of shade required.