UNITED STATES DEPARTMENT OF AGRICULTURE 



t BULLETIN No. 867 { 



^^tr^-^ffv^ Contribution from the Bureau of Plant Industry < 



Contribution from the Bureau of Plant Industry 

 WM. A. TAYLOR, Chief 



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Washington, D. C. 



PROFESSIONAL PAPER 



September 3, 1920 



THE CASTOR-OIL INDUSTRY. 



By J. H. Shrader, formerly Chemical Technologist, Office of Drug, Poisonous, and 



Oil Plant Investigations. 



CONTENTS. 



Page. 



The source of castor oil 1 



Trade and commerce 3 



The inspection or valuation of castor beans. . 7 

 Manufacture of castor oil 9 



Properties of the oil 31 



Uses of castor oil 35 



Conclusions 40 



THE SOURCE OF CASTOR OIL. 



Castor oil is obtained from the seeds of the castor-oil plant (Rici- 

 nus communis), a member of the plant family Euphorbiaceas, 

 which also includes many other species the seeds of which yield fatty 

 oil. The castor-oil plant is now either cultivated or .found growing 

 wild in most tropical countries and in the milder parts of the Temper- 

 ate Zones. In warm countries it is a perennial and often attains 

 the proportions of a tree, frequently reaching a height of 40 feet, 

 but in colder climates it rarely grows 20 feet high and annually dies 

 down with the approach of winter. This plant is extremely variable 

 in size, color of stems and leaves, degree of branching, size and color 

 marking of the seeds, and many other characteristics. 



The seeds of the castor-oil plant are known as "castor beans" in 

 English-speaking countries, and are often mistakenly supposed to 

 belong to the bean family, to which they are in nowise related. Cas- 

 tor beans as they occur in commerce consist of a white, soft, nonfi- 

 brous kernel inclosed in a hard, thin seed coat. This is so brittle 

 that unless care is exercised in handling, it is easily cracked and 

 chipped off, exposing the kernel to the air, with attendant deteriora- 

 tion. This seed coat is usually mottled in appearance and varies 

 in color from a creamy white through pink, golden yellow, green, and 



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