OIL-SEEDS AND OILS 131 



from Malaya and Australia, as well as from India, New Zealand, 

 the West Indies and Mauritius, from Fiji and other islands in 

 the Pacific, and from Kenya Colony, Zanzibar, and the Gold 

 Coast, in Africa. 



CASTOR-OIL PLANT (Ricinus communis). In tropical 

 climates if left to itself it attains a height of forty feet, but in 

 more temperate lands it becomes a bush, while in England it has 

 to be raised from seed every year, and never grows more than 

 four or five feet high. 



It has large smooth leaves cut into seven or more segments. 

 The flowers occur on a thick spike, the male ones at the base 

 and the female ones at the top. They have no petals, but the 

 stigmas of the female ones are long and red in colour, and they 

 give a general effect of redness to the whole spike. The seeds 

 are contained in a three -celled spiny capsule ; they are nearly 

 half an inch long, of a pinkish-grey colour, dotted with 

 brown. 



To obtain the oil the seeds are put under a powerful hydraulic 

 press, and the whitish oily liquid which oozes out is known 

 as cold drawn castor oil. It is further purified by being mixed 

 with water, then boiled and skimmed. The pressed seeds 

 which remain are sometimes heated and then pressed a second 

 time, but they yield an inferior oil. 



Castor oil has many valuable qualities. In India and other 

 parts of the tropics it is used as a lamp oil, and is said to give 

 a whiter light than petroleum or any other mineral or vegetable 

 oil, moreover it makes scarcely any soot. 



It is excellent, too, as a lubricant for machinery of all 

 kinds, but it is specially valuable for use in air-craft as it does 

 not freeze until the thermometer is at 0F., then it slowly 

 congeals to a yellow solid. It is also used for making soap 

 and candles and for dressing leather. 



There are two kinds of seeds, large and small ; lamp oil 

 and lubricants are usually made from the large kind, medicinal 

 oil from the small variety. 



The cake, which remains after the oil has been extracted, 



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