INDUSTRIAL USES OF PLANTS 395 



Olive oil is the most important of the non-drying oils, as 

 well as being the most famous edible oil in the world. It is ob- 

 tained from the fleshy pulp which surrounds the seed of the olive 

 tree, a native of Asia Minor, though cultivated extensively in the 

 Mediterranean region and to some extent in the United States 

 and Mexico, South Africa, and Australia. The finest grades of oil 

 are obtained by hand pressing; lower grades obtained by machine 

 pressing are used as lubricants and in soapmaking. Partly because 

 of the development of native edible oils, olive oil is decreasing in 

 importance as an American table and salad oil. 



Castor oil is best known for its medicinal use which, how- 

 ever, accounts for only about one-sixth of the total amount used 

 in the United States. Its principal uses are in the manufacture of 

 some soaps, certain dyes for textiles and leather, and as a lubri- 

 cant for airplane and marine engines. India leads in the world 

 production of castor seed, although the castor plant, a low grow- 

 ing, short lived perennial tree, is widely grown in tropical and 

 warm temperate regions as an ornament. Formerly some seed was 

 produced in the United States, but the present cheapness of the 

 Indian crop has caused abandonment of American production. 



Peanut oil is expressed from the seed of the common peanut. 

 Gold pressed oil has a light color, fine flavor, and is much used as 

 a salad oil, as an adulterant for olive oil, for butter and lard 

 substitutes, and as a packing oil. Hot pressed oils are used for 

 lubricants, illuminants, and in soapmaking. The residue or cake 

 has a higher food value than any other oil cake, and is valuable 

 as a stock food. The United States is the chief world producer, 

 followed by the West Indies, Africa, and India. 



Coconut oil, the most important of the plant fats, is ob- 

 tained from the dried meat of the coconut, known commercially 

 as COPRA. The coconuts are harvested, husked, and broken open 

 to dry, after which the meat extracts readily. The former crude 

 native methods of pressing are rapidly giving way to machine 

 extraction which yields a better grade of oil to meet the increasing 

 world demands for this product. The Dutch East Indies, Philip- 

 pines, British Malaya and Ceylon are the principal coconut 



