TREE PRODUCTS 139 



sugar products, and they are always in solution. 

 Only when the juices are exposed to the air, as 

 when they exude from an injured surface, do 

 they coagulate to form the gummy or resinous 

 substances that become articles of commerce. 



In some cases the exudate may be separated 

 into two or more commercial constituents. Such 

 is the case with the juice of those trees that pro- 

 duce turpentine. The liquid that flows from the 

 tree, corresponding to the sap of the maple and 

 the latex of the rubber tree, may be evaporated 

 or distilled in such a way as to be changed in 

 part to a solid girnimy or even vitreous substance, 

 and in part to the somewhat volatile fluid familiar 

 as turpentine. 



Turpentine, unlike rubber, was known to the 

 ancients, and was an extensive article of com- 

 merce in classical times. The original tree from 

 which it was obtained is known as the terebinth 

 tree. It is a native of the islands and shores of 

 the Mediterranean and western Asia. 



There are many trees, however, the sap of 

 which has this resinous property, including most 

 members of the family of conifers. The prin- 

 cipal supply of common turpentine, in Europe, 

 is obtained from the so-called sea pine, grown 

 largely in France. The Scotch fir, the Norway 

 pine, and the Corsican pine are other sources. 



