SEWING SILK AND TWIST. 99 



cold soap suds. As the price of Aleppo galls is high, 

 white galls are often used, in the proportion of eight 

 or ten parts of nuts to two parts of Aleppo galls. 

 Dyers have a cauldron on purpose for black, and 

 when the dyeing composition is exhausted, they renew 

 it by what they call a brevet, (refresher.) When 

 the deposite is considerable, it is taken out, and iron 

 filings added to the liquid. The dyeing of the silk is 

 finished by heating the cauldron containing the dye, 

 and stirring it, from time to time, to prevent the sedi- 

 ment from heating too much. 



" The liquor must not boil ; add more or less gum 

 and iron solution ; and, when the gum is dissolved, 

 and the liquid nearly boils, it is left for one hour, the 

 silk, divided into three portions, is then immersed ; 

 each portion in succession. The silk is lightly wrung 

 three times, and aired each time. The great point of 

 this operation is to press out the liquor with which 

 the silk is impregnated ; and, when it is drained, to fill 

 it again therewith ; and, above all, to expose it to the 

 air, which deepens the color. After each portion of 

 silk has been wrung three times, the vat is to be heat- 

 ed and more gum and copperas added as at first. 

 The reheating of the vat is called giving a fire. Two 

 fires are commonly given fora light black, and three 

 for a deep dye; and sometimes the silk is left in the 

 vat, after the last fire, for twelve hours. Commonly, 

 thirty kilogrammes [a kilogramme is 2 Ibs. 3 oz. 5 

 drachms, avoirdupois,] of silk are dyed in one opera- 

 tion. 



" This is technically called a heat. If half that 

 quantity is dyed, only one fire is required for a light 

 black. The dyeing being finished, the silk is rinsed 

 on the rods according to art. 



