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DYEING AND CALICO PRINTING.

the fragments become entangled among the wool, and can only be removed—if at all—by very tedious washing. Hence the woods, &c., should be appliedin the state of liquid extradts.

A further very large quantity of wool* is dyed in the state of yarn. Almostall the wool used in carpets, hosiery, shawls, table-covers, dress-pieces, andall those goods in which the Jacquard loom shows itself a formidable rival tothe printing-machine, is yarn-dyed. Wool is sometimes also dyed in the stateof “ slubbings ” or "slivers.” These are long masses of wool, which, bydrawing out and twisting, become converted into yarn ; they require, indyeing, the same precautions as loose wool. Piece-dyeing holds a very pro-minent position as regards woollen and worsted goods. By far the greaterpart of stuffs, whether consisting of “ all wool ” or of a worsted weft andcotton warp, are dyed in the piece. So, likewise, is the bulk of the cloth madein the present day. The piece-dyer has certain peculiar difficulties to en-counter : the first of these is the possibility of the dye attaching itself morestrongly to one part of the surface of the cloth than to another. If this oncetakes place the piece has a more or less cloudy or spotty appearance, which isvery difficult to remove, and which cannot exist without at once betrayingitself. There is especial danger of this unevenness with dyes which have avery powerful affinity for the fibre, and which are consequently apt to seizehold, in excess, of the first portion of the piece that enters the dye-beck. Toprevent or lessen this tendency certain substances are used called levellers.One of these is sulphate of soda, Glauber’s salt, or sal-enixum, called bymany dyers Sally Nixon. This salt is added to many dye-mixtures, andseems to lessen the affinity of the colour for the cloth to such a degree that—instead of being rapidly and irregularly deposited upon the surface—it inter-penetrates the whole equally, and produces an even or “ level ” shade.

With the aniline colours the risk of irregularity is very great, especially ongoods woven from fine, soft wools. If any particles of the dye have escapedperfedt solution, and remain suspended in the beck,—if the methylated spiritfrequently used as a solvent has partially evaporated, leaving some of thecolour in the form of a bronzy scum on the surface,—or if the liquid has beenworked up into a froth or “ flurry ” by the rapid passage of the pieces throughthe beck,—spots and stains are almost inevitable. To prevent these incon-veniences glycerin may be used in dissolving the dye, or may be subsequentlyadded to the bath. It does not allow the colour to separate out, and preventsbronzing and “ flurry.” With magenta, small quantities of white soap areused by some dyers—an addition which levels the colour, and gives a slightlyredder tone. A decodtion of Panama bark [Quillaja saponaria) is sometimesadded to the dye-beck, with good effedt, for the same purpose. Pieces spottedand stained, “ flushed ” with aniline colours, may be considerably improvedby being winced in this decodtion.

Panama bark is also used for another purpose, which it may not be out ofplace to mention here. If it is desired to produce upon woollen or worstedgoods the purest and most lustrous whiteness,—whether for sale in that stateas " double-stove whites,” or for being dyed particularly light and brilliantshades, such as light roses, light, greens, peaches, pale violets and blues, &c.,

* The distinction between wool and worsted is, from a tinctorial point of view, unimportant.