266 TROPICAL AGRICULTURE 



While there are differences in the physical properties of 

 oils obtained from these trees, there has been much confusion 

 in naming the trees and in properly labeling the oils in the 

 past. Commonly, the term Chinawood oil, tung oil, nut oil, 

 and various other phrases have been applied indifferently to 

 the oil coming from any one of the three already mentioned 

 species of Aleurites. These trees are native of China, Japan, 

 Tonkin and Annam. They have been introduced, however, into 

 Madagascar and the Southern States in this country. It has 

 been found that the tung oil tree A. fordii will thrive in Flor- 

 ida, South Carolina, Alabama, Louisiana, Mississippi, Georgia, 

 Texas, and California. It will withstand temperatures in 

 winter as low as 14 F. and it has been found to yield in these 

 States a satisfactory quantity of nuts which produce an oil 

 of good quality. Since the United States imports about 5,000,- 

 ooo gallons a year of Chinawood oil, it would seem desirable 

 to attempt the commercial growing of the wood oil tree on 

 some of the cheap and rough lands of the Southern States. 



The seeds of the tung oil tree contain about 53 per cent, of 

 oil and yield 40 per cent, of oil by pressure. Cold pressed oil 

 is light yellow in color, while hot pressed oil is dark brown. 

 The specific gravity of tung oil is 0.94 and the iodin number 

 166.7. 



The present world's production of Chinawood oil is about 

 30,000 tons a year. It should be remembered that China 

 probably uses twice as much oil as is exported from that 

 country. The trees are commonly planted 20 feet apart both 

 ways and may be expected to bear a profitable yield at 5 years 

 of age. In fact, in Florida, some of the trees have begun 

 bearing at the age of 2 years. 



Candlenut oil is a well known paint and varnish oil, ob- 

 tained from the seeds of A. triloba, also known as A. moluc- 

 cana. Candlenut oil has been known by a considerable variety 

 of names in the trade, such as country walnut oil, kekune oil, 

 artists' oil, Bankul oil, Eboc oil, Spanish walnut oil, Belgaum 



