CAOUTCHOUC. 475 



stance, and into guaiacol, C 7 H 8 2 (p. 305), a liquid. 

 When the resin is subjected to destructive distillation, 

 there are formed besides these, creosol, C 8 H 10 2 (p. 309), 

 and several other bodies. 



14. Acaroid resin, from Xanthorhoza hasUUs, a tree 

 growing in New Holland. Yellow colored; yields 

 picric acid abundantly when heated with nitric acid, 

 and phenol when subjected to distillation. 



15. Dragon's blood, from a number of trees in the 

 West Indies. Small, dark-brown, opaque lumps ; in 

 the form of powder blood-red ; soluble in alcohol with 

 red color. Contains a little benzoic acid. Yields 

 toluene when distilled. 



16. Amber, a resinous product of extinct coniferse, 

 occurring in lignite beds. Colorless, yellow or brown- 

 ish yellow, transparent or translucent, hard, often in- 

 closing insects. Fusible, undergoing decomposition, 

 however, the succinic acid contained in it being volati- 

 lized. In addition to this acid it contains a volatile 

 oil and two resins, soluble in alcohol and ether. Its 

 principal mass consists of an amorphous substance, in- 

 soluble in alcohol, fatty and volatile oils, as well as in 

 alkalies. 



2. Caoutchouc. 



Flows from incisions in various trees growing in 

 South America and the East Indies (especially several 

 varieties of Siphonia and Ficus elastica), as a juice of 

 creamy consistence which dries up, forming caoutchouc. 

 The juice contains albumen in solution, in which the 

 caoutchouc is suspended in the form of globules. 

 "When heated, the albumen coagulates, and the caout- 

 chouc globules adhere together with it in coagulated 

 masses. Pure caoutchouc, as it does not occur in com- 

 mence, is colorless and transparent. 



Its characteristic property is elasticity. It loses this 

 property when kneaded for a long time between warm 

 rollers, and is converted into an homogeneous, black, 



