GUMLACORSHELLAC. 39 



make their appearance, and in October or November, when the 

 red liquor gets exhausted, 20 or 30 young ones bore a hole 

 through the back of their mother, and come forth. The empty 

 cells remain upon the branches. These are composed of the 

 milky juice of the plant, which serves as nourishment to the 

 insects, and which is afterwai'ds transformed or elaborated into 

 the red coloring matter which is found mixed with the resin, but 

 in greater quantities in the bodies of the insects, in their eggs, 

 and still more copiously in the red liquor secreted for feeding 

 the young. After the brood escapes, the cells contain much 

 less coloring matter. On this account the branches should be 

 broken off before this happens, and dried in the sun. In the 

 East Indies this operation is performed twice in the year ; the 

 first time in March, the second in October. The twigs incrusted 

 with the radiated cellular substance, constitute the stick lac of 

 commerce. It is of a red color, more or less deep, nearly trans- 

 parent, and hard, with a brilliant conchoidal fracture. The 

 stick lac of Siam is the best ; a piece of it, presented to me by 

 Mr. Rennie, of Fenchurch street, having an incrustation fully 

 one quarter of an inch thick all round the twig. The stick lac 

 of Assam ranks next ; and last, that of Bengal, in which the 

 resinous coat is scanty, thin, and irregular. According to the 

 analysis of Dr. John, stick lac consists of 



An odorous common resin 80.00 



A resin insoluble in ether ....... 20.00 



Coloring matter, analogous to that of cochineal . . 4.50 



Bitter balsamic matter .' . . . . . . 3.00 



Dun yellow extract . 0.50 



Acid of the stick lac (laccic acid) 0.75 



Fatty matter, like wax 3.00 



Skin of the insects and coloring matter .... 2.50 



Salts . 1.25 



Earths 0.75 



Loss 4.75 



120.00 



