994 JOURNAL 01' FORESTRY 



by the use of one-year seedlings. The trees begin to bear in from 3 to 

 7, usually 4 to 6, years, depending upon the variety and the site, and 

 continue to do so for about 10 years. If conditions permit, other 

 crops, such as tea, are grown between the trees for the first two or three 

 years. 



The fruits, which look like large hickory nuts, ripen in September, 

 whereupon they burst open and release the 3 to 5 triangular seeds, 

 each of which is about as large as the end of one's thumb. In practice 

 the fruits are gathered before they are ripe, are then placed in iron 

 pans about two feet in diameter and stirred about over a good fire until 

 the husks are parched and fall away from the seeds. Another process 

 is the pit method, in which the husks are disposed of through natural 

 fermentation. 



"The process of extracting the oil is very simple. The seeds are placed in a 

 circular stone trough where they are crushed by a heavy stone roller drawn 

 by buffalo, cow, or ass. The pulverized mass is then partially roasted in shal- 

 low pans, after which it is placed in wooden vats, fitted with wicker bottoms, 

 and a further steaming process takes place over boiling water. Next with the 

 aid of an iron and straw, the meal is made into circular cakes. These cakes 

 are arranged edgeways in a large press and when full, the pressure is applied. 

 This is usually accomplished by a system of wedges which are driven in one 

 after another by means of a huge battering ram until the brown, somewhat 

 watery and heavy smelling oil is crushed out into the vat below. The oil is 

 then collected in vessels, is slightly heated, and after being freed from sediment 

 by straining through coarse grass cloth is ready for market. Often, however, 

 the heating process is carried too far, and the oil becomes dark brown instead 

 of retaining its desired light yellow color. As a rule the oil yield is about 40 

 per cent of the original weight of the kernels. The refuse cakes are used as 

 fertilizers." 



"The wood oil consists chiefly of the glycerides of oleic and elacomargaric 

 acids. According to Fahrion it contains 2 to 3 per cent of saturated fatty acids 

 and about 10 per cent of oleic acid. On keeping wood oil becomes jellified and 

 solidifies partly. It is readily identified by its strong characteristic smell. Its 

 specific gravity is higher than that of any known oil excepting castor oil. On 

 account of its pronounced drying power, wood oil has been frequently used as 

 a substitute for linseed oil, whose drying properties are not as strong. The 

 oil is very poisonous when fresh. The refractive index of wood oil is higher 

 than that of any known fatty oil. The tung kernels contain about 53 per cent 

 of oil but the secured yield of oil under native processes amounts to only 40 

 per cent." 



The author believes that the yield and richness of the nuts can be 

 materially improved by proper breeding and cultivation. He advocates 

 the use of simple extracting machinery which will remove more of the 



