THE BESINS. 257 



or cloudy, and has a strong balsamic odor. That from 

 New Caledonia is yielded by D. ovata. Its odor is also 

 balsamic, its color and transparency variable. The Manila 

 Copal flows from incisions in the trunk of Vatcria indica 

 (family Dipterocarpece). It hardens quickly, and has a 

 faintly balsamic odor. The South American Copal collects 

 in masses on the stems and roots of several plants, espe- 

 cially on Bymencea courbaril. The surface is uneven and 

 covered with a thick crust. The color varies from yellow 

 to brown ; it has an odor not unlike that of glue, and a 

 bitter taste. Copal is very complex in composition. The 

 large pieces are used iu turnery. It is the most important 

 resin for the manufacture of varnishes. 



225. Guiac, or Guiacum, is yielded by Ouiacum offi- 

 cinale, a tree belonging to the order Zygophyllm, which is 

 closely related to the Geranium family. The tree grows to 

 the height of twenty or thirty feet, has very hard dark-red 

 or blackish heart-wood, used in making ship's blocks, 

 pulleys, etc. The resin flows spontaneously (in small 

 grains), or after incisions are made (in large pieces). 

 Sometimes long sticks of the wood are bored longitudinally 

 and held over the fire, when the resin flows out and is col- 

 lected iu calabashes. Occasionally, but not often, it is 

 obtained by boiling the finely-divided wood. The resin is 

 brittle, of a brownish-black color, or greenish when long 

 exposed. When fresh it is very lustrous. The odor is 

 weak and peculiar, the taste pungent. It contains many 

 resinous acids, some gum, and a small quantity of mineral 

 substances. This resin is much used in medicine. 



227. In a very limited district (Balsam Coast) of St. 

 Salvador, Myroxyion sonsonatense is found, and from it is 

 obtained the Balsam of Peru. This tree belongs to the 

 17 



