oct. — dec. 1857.] Oils of Southern India. 



43 



Wood Oils. 



91 to 100. Wood oils. 



The class of substances called " Wood oils" form the connecting 

 link between the oils and resins of the natural kingdom. They 

 consist of a volatile oil, holding in solution a resin, and are gene- 

 rally classed under the head of Balsams. They are obtained from 

 various trees of the order Dipterocarpeae, some of which also yield 

 the dammers of commerce. 



The mode of extracting the oil, is similar to that adopted for ob- 

 taining the solid resin. It is best described, in the words of a con- 

 tributor to the Madras Exhibition of 1855, who says " About the 

 end of the dry season, that is in March or April, several deep in- 

 cisions are made with an axe into the trunk of the tree, and a 

 good sized piece, scooped out. Into these holes, fire is placed and 

 kept burning until the oil begins to run, when it is received into a 

 bamboo, and allowed to run slowly drop by drop." 



The oil, when freshly obtained from the tree and allowed to rest, 

 separates into two layers, the upper consisting of a clear chesnut 

 colored liquid balsam, and the lower being a flocculent deposit of 

 the more solid resin, of a light ash color. 



They are much used as natural varnishes for in-door work, but 

 are very brittle, and require constant renewal. Perhaps the admix- 

 ture of a certain proportion of some drying oil, would remedy this 

 defect. They are said to be used also in the manufacture of Li- 

 thographic inks. 



These oils are chiefly imported from our Burmese possessions 

 and the Islands in the Straits of Malacca, and are usually known 

 by the name of the districts, from whence they are brought. 



The Camphor wood oil is a purely volatile substance, without 

 any admixture of resin. It is the produce of the Dryohalanops 

 Camphora. It is used in the Straits as a substitute for turpen- 

 tine, and sells at 15 to 20 cents a bottle. 



Many substances called „ wood oil" by Native doctors, are little 

 else than varieties of tar obtained by the destructive distillation 



