278 TROPICAL AGRICULTURE 



apart in rows 4 feet apart, but in tropical countries the plant- 

 ing distance is 5 or 6 feet both ways. The castor oil industry 

 in India is a very important one. The oil is highly valued 

 for use in lubricating machinery, for dressing hides and skins, 

 for illuminating purposes, in the manufacture of soap and can- 

 dles, and as a medicine. Cold pressed oil gives a more brilliant 

 light than oil obtained from boiled or roasted beans. The press 

 cake obtained from castor oil mills is widely used as a fertilizer 

 for rice, potatoes, and sugar cane. In India the beans are 

 picked from the seventh to ninth month after planting. The 

 yield ranges from 500 to 900 pounds of beans per acre. 



Peanuts are grown as a commercial crop chiefly in the East 

 . Indies, Java, Mozambique, United States, Togo, southern Ni- 

 geria and the West Indies. Senegal exports 200,000,000 pounds 

 of peanuts annually to Europe. In the commercial preparation 

 of peanut oil it has been found that the first cold expression 

 yields the best oil. This oil is used as a salad oil. A second 

 grade of peanut oil is also used for salad purposes, being sold 

 at a lower price. The third grade of oil is employed largely in 

 the manufacture of soap. High-grade peanut oil is quite widely 

 used as an adulterant of olive oil and in preserving sardines 

 and for other culinary purposes. Peanuts yield 32 per cent, of 

 oil by the ordinary commercial methods. The oil cake which is 

 thus obtained as a residue contains 8 to 9 per cent, of oil and is 

 an excellent cattle feed. The chief tropical producing countries 

 export nearly 700,000 tons of peanuts annually for use as a 

 source of oil. 



Rice oil, obtained from rice bran and meal, has come to be 

 a commercial product of considerable importance. Unmilled 

 rice contains 2 or 3 per cent, of oil. Most of this oil is located 

 in the outer portion of the grain and is therefore removed in 

 milling. In the rice mills of Rangoon it has been found that 

 the bran contains as high as 20 per cent, of oil. Rice oil com- 

 monly shows a rather high acidity. It is extracted by com- 

 mercial solvents and is chiefly used in the manufacture of soap. 



