OILS AND OIL SEEDS 341 



in the stem of the tree and Lighting, within the cavity 

 so formed, a small fire from broken coconut shells or 

 wood chips. The heat from the flame draws the wood 

 oil down, which trickles into the back or apex of the 

 cavity cut into the wood, from which it is removed later. 

 This crude process of extraction is both wasteful and 

 destructive to the tree, and many splendid " Dorana " 

 trees are completely destroyed thereby. This is the more 

 deplorable as the tree is by no means abundantly dis- 

 tributed in our forests, and where it occurs it is usually 

 confined to restricted gregarious clumps or clusters of 

 no great extent. 



" Dorana " oil is one of the ingredients used in the 

 preparation of pigments for Kandyan paintings. It is 

 generally used mixed with the resin of the " Hal " tree 

 (Valeria indlca. Linn.), the combination making an ex- 

 cellent varnish. 



The oil is also employed in a native method of catching 

 the rice-bug (Leptocorisa varicornis\ which is often very 

 plentiful and exceedingly disastrous to the rice crop. 

 In this process, known in Singhalese as " Bokkugewima," 

 the wood oil is added to the latex of a species of Wil- 

 lughbeia, or a Palaquium, and mixed into a viscous mass. 

 This fluid is then placed in a shallow scoop, or boat- 

 shaped vessel, made from closely plaited bamboo, that 

 is sufficiently porous to allow the mixture to ooze through 

 slowly so as to cover the lower sides of the apparatus 

 with a thick, gummy slime. The scoop is attached to 

 a light frame that in turn is attached to a long slender 

 pole by means of which the scoop is swept over the 

 rice fields, just at the time the young ears of rice are 

 beginning to ripen, the rice-bugs being caught on the 

 sticky slime. In parts of the Ratnapura District of the 

 Sabaragamuwa Province this form of "bug-liming" is 

 much in vogue, but where the fields are very large there 

 are obvious practical objections to its general application. 

 ' Dorana " oil is believed to be of value as a remedy 

 for rheumatic affections. 



Another wood oil obtained from an allied tree (Dip- 

 terocarpus zeylanicus, Thw.) is used for caulking cracks 

 in boats or canoes. It is more resinous than the last, and 



