WOOD OIL 147 



is taken as 2000 Ibs. Carefully planted and treated in 

 the same way, it is probable that rama would give as 

 high a return, judging from the growth seen in the country. 

 Jute in India, it should be remembered, is a manured 

 crop, but rama in West Africa is only manured in the 

 northern districts of Northern Nigeria, being cultivated 

 without any special care in the Niger Valley. 



WOOD OIL. Following the order of value shown in 

 the list of exported products, wood oil appears next. 

 This is the oleo-resinous exudation obtained from 

 Daniellia thurifera, a tree belonging to the Natural Order 

 LEGUMINOSM, and allied to some of the species from 

 which the West African copals are procured. This tree 

 is commonly found in the dry country, but occurs also 

 in the damp forests, where it frequently attains large 

 dimensions. The wood oil is collected in many parts of 

 West Africa, and is used as a substitute for " balsam of 

 copaiba ' ' in native medicine. The concreted resin formed 

 on the trunks of the trees by the borings of coleopterous 

 larvae is used for burning as incense. 



The native use of wood oil in place of " balsam of 

 copaiba " induced merchants trading upon the Niger to 

 export it, and at one time a fair quantity was sold in 

 England. This export trade has recently diminished to 

 a large extent. 



The substance is an oleo-resin, and when free from oil 

 has a similar appearance to copal. Upon examination of 

 the resin, it has been found to be dissimilar in properties 

 from the various freshly exuded resins which enter the 

 market under the name of recent or soft copal. (Bulletin 

 of the Imperial Institute, vols. vi. [1908] and xiii. [1915].) 



The mode of collecting wood-oil is somewhat destruc- 

 tive, as, in order to procure an excessive flow, a hollow 

 is scooped out in the main trunk and a fire is kindled 

 in the hole thus made. The oil commences to flow 

 rapidly after the fire is extinguished, which it is necessary 

 that it should be before a large quantity of oil has exuded, 

 on account of the inflammability of the latter. 



The application of fire to the trees does not appear 

 to kill them, but they are rendered liable to attacks of 

 noxious insects, and are often broken off by winds. 



In addition to the local use of the oil for maladies 

 for which balsam of copaiba is generally employed, the 



