No. 129.] 469 



may be obtained from logwood by a solution of tin. It is used 

 for blacks, extensively, and different shades of gray, and not un- 

 frequently with Brazil-wood. No coloring matter in use affords 

 a more choice variety of dyes than logwood : they are rarely per- 

 manent, however. Cochineal is considered, very justly, the most 

 valuable of all dyeing drugs, producing a superb scarlet- crimson 

 and carmine. Wlien America was discovered it was found in 

 Mexico, and imagined to be the seed of some plant. It is an in- 

 sect, known as the coccus cacti, and feeds upon the cactus 

 opiuntia, commonly called the prickly pear. Two kinds are 

 made use of in Mexico, known as grana fina and grana sylvestra ; 

 the first is large, and yields a large quantity of coloring; the 

 other is small, and but little used. The insect is killed, and the 

 dye extracted by immersion in hot water. Cochineal retains its 

 coloring principle perfectly for one hundred and twenty-years. 

 A variety of beautiful colors may be obtained from the coloring 

 matter of this insect by mixing with it different mordants. By 

 the addition of alum to a decoction of cochineal, carmine or lake 

 is formed. Carmine has been made from kermes, (cocceus ilicis,) 

 an insect found in Asia, apd is a very ancient dye, not inferior to 

 cochineal. The ancient Brussells and Flemish tapestries were 

 dyed with kermes, and although the colors have lasted two hun- 

 dred and fifty years, they are still brilliait. 



In Poland they have a small round inseot called Czerwiec, tbe 

 coloring matter of which l? used to dye silk, wool, horse hacT) 

 and the nails of the ladies. 



Lac is an animal coloring matter, yielding a red dye. It ig 

 produced in the East Indies by a winged insect called Coccus 

 Lacca. This insect deposits its eggs on the branches of a shrub 

 called Croton lacciferum, and then covers them with this colo- 

 ring substance, lac, which defends them from external harm, 

 and affords food to the maggot as it advances in its strength. Tha 

 natives of Assam, invite the flies to deposit their eggs, by be- 

 smearing the branches with substances grateful to them. 



Archil is manufactured by pounding the lichen called Rocella 

 tinctoria and forming into a paste. 



