428 TRANSACTIONS OF THE 



The broken branches with the lac incrustations upon them at 

 various distances, is called in commerce stick-lac. The coloring 

 matter exhibited by grinding stick- lac and then treating it with 

 water, constitutes seed-lac. 



The resin in stick-lac is, 68 per cent. 



do seed-lac is, 88 do 



do shell-lac is, 91 do 



Exports of it from Calcutta, twelve months ending August 31, 

 1855: 



Shell-lac. 



To Great Britain, Indian maunds,* 26,147 



To France, do 7,609 



To North America, do 124,630 



Dragon's blood is collected from the seed-vessels of a Eupho- 

 ribaceous tree, the Rottlera tinctora of Roxburgh, occurring in 

 Arabia, Eastern Africa, and various parts of India. It is highly 

 esteemed by the Chinese. There are two kinds in Socotra. The 

 best is of a dark crimson color. This gum was the cinnabar of 

 the ancient Greeks. In the time of Dioscorides it was believed 

 to be the indurated blood of the dragon. A red juice flows from 

 the wild nutmeg, an incision being made in the bark. Gum 

 Guiacum from the lignum vitse. In May it exudes from incisions 

 in the tree. Also made by burning the wood with a hole bored 

 through it; so that the heat drives the gum to the center, where 

 it comes out and is received in a calabash. Also by boiling the 

 chips in water. 



Fragrant Incenses. 



In the East, Gum Benjamin, (the most costly,) Olibanum, (the 

 ancient Frankincense,) Gum Benjamin, or the Benzoin of Com- 

 merce, the product of a lofty tree of Siam, Sumatra and Java, and 

 also of a smaller tree in Borneo. 



AsPHALTUM. 



The pitch lake of Trinidad, covering a surface of about a mile 

 and a half in length, by one-eighth of a mile in width. Billions 

 of tons of the Asphaltum seem to have here boiled up from the 

 bowels of the earth. It is extensively used. Mixed with peb- 

 bles and sand, makes good roads, floors on the ground, &c. The 

 best and latest account of it is in Silliman's American Journal of 

 Science and Art, vol. 20, page 155, for September, 1855. 



* Maund, 82 lbs. English. 



