DAMMAR AND WOOD OIL. 89 



Dammar and Wood Oil. 



By H. N. Ridley, 



Dammar is the resin exuded from various trees when wounded. 

 The trees producing it belong- chiefly to the order Dipterocarpece, 

 and to the genera Skorea, Hopea and A nisoptera, but the Malays 

 also class as Dammar resins derived from certain species of Cana- 

 rium, and Triomma (Burseracsce) and Calophyllum (Guttiferce). 



The resins are exuded from wounds in the trunk or branches, 

 or sometimes a tree is hollow in the centre, and the space is filled 

 or partly filled with the dammar, which thus forms a cast of the 

 hole. At times it is exuded beneath the bark when it sets in the 

 form of a plate or lamina, or it may drip slowly from a broken 

 or cracked bough, so as to form stalactitic pipe- like masses on 

 the injured part, and sometimes a stalagmitic mass on the ground 

 below. The exudation does not commence immediately the 

 wound is inflicted, and is produced very slowly, at first like tur- 

 pentine, but soon setting into a hard crystalline mass. Even 

 quite young trees, such as slwreas, produce the dammar when the 

 stem or twigs are broken or bored by insects. The masses of 

 dammar are not only modified in form by their method of pro- 

 duction but also in colour and transparency. Many of the 

 native and trade names have reference rather to the form and 

 colour of the resin mass than to the tree from which it is derived. 

 Thus Cat's-eye Dammar (Damar mata kuching) is a transparent, 

 pale, yellowish resin, usually in small pieces, and can be derived, 

 I believe, from almost any of the Hopeas. Damar claying, a 

 dark brown, often handsomely marbled resin, often occurs in 

 large masses showing the form of the hollow of the tree in which 

 it was exuded. A very beautiful dammar of which I obtained a 

 specimen from Johore was a clear sea green. It was found buried 

 in the ground as is often the case, and there was no clue as to 

 what tree produced it. When oxidised the resin becomes opaque 



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