VIOLETS : (1) Gentiana Violet (11 lb.).—Boil 2 lb. 3 oz. sumach, or 61 oz. tannin, in water, and steep the yarns overnight in the clear solution. Wring up next morning, and dye in a beck at (165° F.), containing 9 oz. gum arabic, adding more or less of the dissolved colour according to shade. Wring, and dry.
(2) Or,—Make up a beck at 50° (122° F.) with 80 gr. tannin for eaoh 2 lb. 3 oz. cotton, and turn well for 4-5 hours. Wring, and enter into the colour-beck at 43° (110° F.), adding 775 gr. acetic acid for 11 lb. cotton. Wring, and dry.
(3) Medium Violet (100 lb.).—Mordant yarns in stannate of soda at 8° Tw. ; sour at 1/° Tw. with dilute sulphuric acid ; wasb off with cold water, and dye with I lb. aniline violet accerding to shade. Heat up to about 71° (160° F.).
YuLLows : (1) Yellow (11 lb.).—Dilute red liquor to 61° Tw., and steep the clear yarns overnight in the cold. Extract 4 lb. 6 oz. quercitron bark in boiling water, let cool down to 75° 167° F.), and dye the yarns to shade. If a brighter shade is desired, add to the bark liquor 11 oz. tin crystals.
(2) Feat Fallow (60 lb.).—Boil 6 lb. brown sugar of lead in 6 gal. water till dissolved; add this solution to sufficient cold water. Work the yarns 5 turns, and wring. Dissolve 2 lb. bichmmate of potash, and add it to sufficient cold water. Work yarn 5 turns, wash twice in cold water, and dry.
Mr.ouetteest. Armaiwzs.—The mechanical appliances used in dyeing vary very much, accord ing to the class of the material and the scale of the operations. Unspnn wool and rags are simply laid in the dye-becks, and turned as may be required with the dyer's pole. Yarns and woven goods on the small scale are dipped and turned in the dyeing-baths by band, the yarns being generally supported on sticks, passed through the hank, and resting upon the tub, vat, or cistern. On the large scale, the goods are turned by maohinery. In piece-dyeing, very great use is made of the padding machine, a kind of trough or cistern, fitted with rollers both above and below the surface of the liquid, over which the pieces pass with a regular speed, the dye being thus squeezed into the fibre,—an arrangement which greatly facilitates the regular deposition of the colour. These
machines are especially used for mordanting cotton piece-goods, and for applying such colours as nre worked in the cold. For dyes which require a high, and especially a boiling, heat, the dye-pans are fitted with winohes, either fixed or movable, and generally capable of being turned by power. The piece, being rolled up on a wooden roller, is allowed to uncoil itself, and gradually descend into the liquid. When it is run out, the motion is reversed, and so on till the 'Sleek is dyed up to shade. In piece dyeing, great rapidity and regularity of motion are of the first importance, especially at the beginning of the operation ; with dyes which have a strong affinity for the fibre, a slow movement allows some parts of the cloth to absorb too much of the colours, and a stoppage often leaves a line across the piece, corresponding with the surface of the liquid—the point at which action is greatest.
Fig. 583 will convey an idea of a dye-beck fitted with rollers :—a is a reel, having long wooden spans on its circumference, and being set in motion by a driving shaft. Steam is admitted, if required, by the perforated pipe b. The 583.
pieces of cotton, stitched together at their ends, pass over the reel in the direction of the arrows, and fall on a sloping ledge g, on one lido of the beck, whence they pass under the rollers c d. Its general dimensions are 6 ft. in length, 4 ft. in width, and 4 ft. in depth.
• • The material of the pans, &o., in which dyeing is carried on, is of great importance. Accordiug to the colour used, the vessels may be of wood, iron, block-tin, slate, sandstone, &c. They must he selected so as to bo incapable of yielding to the dye-bath any substance that could interfere with the process. Thus an iron pan or beck should on no account be used for dyeing any bright or light colour, especially if acid _ mordants or dyes are present. The most scrupulous cleanliness—one might say chemical cleanliness—is an essential iu successful dyeing.