No. 129, j 471 



each other. Logwood is used as an aid, and adds much to the 

 beauty of the black. To receive a peifect black, the cloth should 

 be first dyed bluej and to every 100 pounds, six pounds of sul- 

 phate of iron, twenty-nine pounds of logwood, and six pounds of 

 nut galls should be used. When dyed it is washed until the 

 water passes off colorless, 



Brown is a compound color, and is formed by combining wal- 

 nut peels, the root of the walnut tree, sumach, and the bark of 

 birch. The cloth to be dyed is boiled in a decoction of these 

 substances, which produces a permanent brown color. 



Calico printing, that so much surprised Herodotus, Strabo, and 

 Pliny, is dependent upon the art of dyeing. The cloth is figured 

 to suit the taste of the manufacturer, and the spaces within the 

 figure, intended to receive the dye, are impregnated with a mor- 

 dant — this mordant having an afiinity for the dye forms a lx)nd of 

 imion with it, and absorbs the dye so permanently that washing 

 will not remove it, though it eradicates the stain from the un- 

 mordanted parts. This style of calico printing was practised in 

 Turkey and Asia early in the day by means of blocks ; and the 

 goods were exported to other countries, and considered very 

 beautiful. In the year 1676, calico printing was commenced in 

 London, and in 1700 the importation of prints from China, India, 

 Asia, and Persia, was prohibited, with the view of protecling 

 home manufacturers, which has always been the policy of Great 

 Britain, and to that policy she owes her present greatness. The 

 dye stuffs principally made use of by calico printers, are weld, 

 indigo, quercitron bark, red madder 3 these are mixed with nu- 

 merous mordants, and thickened with either of th e following 

 substances ; gum arable, gum senega], dextrine, rice, starch, fiour, 

 jalep, potato stawh, &c. 



The mineral colors used by dyers are — chromate of lead, which 

 produces a very bright yellow ; antimony orange, a red ; arseni- 

 ate of chromium, a green ; subchromate of lead, an orange red 5 

 hydratcd peroxide of manganese, a brown j prussiate of copper, 

 a cinnamon color ; arsenite of copper, a green — the color of grassy 

 Prussian blue. 



