COT 



COT 



Tlie fire is removed, and the liquor I 

 passed through a hnir sieve when 

 moderately cool. A portion of the li- 

 quor is then drawn into a baih, the 

 yarn or cloth well soaked, wrung or 

 pressed out, and spread to dry. Some 

 fresh liquor is then added to the hath, 

 and fresh cotton used. 



When sumach is used, double the 

 weight is added, and the liquor is 

 merely infused in hot water, and not 

 boiled. \Miere a mixture is used, 

 the galls and sumach are prepared 

 separately and the liquors mixed. 



2d. Alvming. — This preparation 

 serves for very many colours. Four 

 ounces of clean alum are used for 

 every pound of cotton ; the solution 

 is made in a copper of thirty gallons, 

 at 122° Fahrenheit, that amount of 

 water serving for one hundred pounds 

 of cotton. The cotton is introduced 

 into the liquor when at 98° Fahren- 

 heit, well worked, taken out, and 

 wrung or pressed, being placed to 

 dry in the shade. Cotton usually re- 

 quires a second, and even third im- 

 mersion before it is fully prepared ; 

 it should be kept moist for twelve 

 hours, and dipped only after two or 

 three days from the preceding pro- 

 cess. It must be well washed before 

 colouring to remove any uncombincd 

 alum. I'his is so common a prepar- 

 ation that dyers keep the solution in 

 tuns to be drawn off and warmed 

 when wanted. The mordant is some- 

 times prepared for delicate colours by 

 addingone ounce of carbonate of soda 

 for every pound of the alum. Ace- 

 tate of alumina prepared with sugar of 

 lead, alum, and a little potash, is used 

 to produce fine madder reds, weld 

 yellows, and other brilliant colours : 

 it is used cold, and at 4° Baume. 



3d. Mordants. — These are solu- 

 ble mineral bodies which possess a 

 twofold affinity for the staple and the 

 colour. Acetate of alumina, and iron, 

 and solution of tin are the most im- 

 portant. They are applied to certain 

 parts of the cloth to produce peculiar 

 colours, and are also employed in 

 different degrees of strength in-solu- 

 tion for the production of light or 

 deep tints. Thus acetate of iron 



208 



with madder brings out every shade 

 from pale violet to black. Hence 

 mordants are not only added by bath, 

 but mixed in a paste with starch or 

 gum to hinder them from spreading 

 over the surface of the web. In this 

 way more is used than stains the 

 cloth, and steps are to be taken after 

 the preparation is fixed to remove 

 any part of the mordant that is un- 

 combincd ; this is done by scouring 

 in a bath containing fresh cow-dung, 

 which takes off tlie iron or alumina 

 without allowing it to mix with oth- 

 er parts of the web. The process is 

 called dunging. 



4th. Dije baths are of two kinds. — 

 Colour baths, which are used to ex- 

 tract the colour, except in the case 

 of madder, which is used in powder. 

 Dye baths are the solutions in wiiich 

 the web or yarn is pressed to attain 

 a stain ; they usually require a heat 

 of 90= to 100° Fahrenheit, although 

 some are used cold. See the Col- 

 ours. 



5th. Washinnr after Dyeing. — This 

 is a delicate operation, as the uni- 

 formity of tint depends on it. " A 

 well -planned dye-house should be 

 an oblong gallery, with a stream of 

 water flowing in an open conduit ii\ 

 the middle, a series of dash wheels 

 arranged against the wall at one side, 

 and of dyeing coppers, furnished with 

 self-acting winces or reels, against 

 the other. The washing may be done 

 by hand, by the rinsing machine, or 

 dash wheel, according to the stuff; 

 and they may be stripped of the wa- 

 ter either by the jack and pin, by the 

 squeezing roller, or by the press. 

 \^"ooden pins are placed in some dye- 

 houses on each side the wash cistern 

 or pool. They are somewhat coni- 

 cal, one foot and a half high, three 

 inches and a half in diameter at the 

 base, one inch and a half at the top, 

 and fixed firmly upright, and at a lev- 

 el of about three feet above the bot- 

 tom of the cistern, so as to be handy." 

 — {Ure's Encyclopcr.dia.) 



COTTON "GRASS. Several spe- 

 cies of Eriophorum have a small cot- 

 tony tuft from their summits. They 

 are of trifling importance. 



