40 BULLETIN 867, U. S. DEPARTMENT OF AGRICULTURE. 
The potassium soap of this oil is used as a solvent for water- 
insoluble substances, as the ethereal oils, cresols, and synthetic 
perfumes. : 
The extensive use of castor oil in medicine is due to its purgative 
property. Just to what this is dueis a mooted question. Some think 
that the presence of small amounts of ricine or some other impurity 
imparts to the oil this property, which is lacking in the pure glycerid 
or oil. Others claim that this property is characteristic of ricinoleic 
acid (the acid radical of the oil) and quote in support of. their con- 
tention the fact that pure ricinoleic acid itself is purgative. On the 
other hand, the statement that castor oil extracted from the seeds by 
alcohol is more effective than that made by expression lends color to 
the belief that the solvent plays a selective réle in extracting more of 
the substance which possesses the purgative property. 
Much effort has been expended in attempting to remove from castor | 
oil that property which makes it so repugnant to the taste and smell. 
Simple deodorization in a vacuum deodorizer is not altogether 
satisfactory. Everyone is conversant with the corner druggist’s 
effort to mask it in soda water, peppermint, and other ‘‘sandwiches.”’ 
Coloring it and adding a tincture of some of the common spices is 
about as satisfactory as any method. The following rather unique 
concoction is quoted (J. King, King’s American Dispensary) for the 
reason that if such an unpleasant product as castor oil can be made 
to simulate a custard, even remotely, the fact should be made known 
to all: 7 
I find it a very pleasant mode of administration to boil the dose of oil with about a 
gill of good sweet milk for a few minutes, sweeten with loaf sugar and flavor with 
essence of cinnamon or other favorite aromatic; it somewhat resembles custard in its 
taste and appearance and is readily taken. by even the most delicate stomach. 
CONCLUSIONS. 
It is thus seen that although castor oil is one of the minor oils, its 
industrial use is increasing in a marked degree. While it is more 
widely known for its medicinal properties, its use is being constantly 
extended in a variety of industries. 
The general method of manufacturing the oil in this country has 
been by crushing the beans in cage presses, but it has been found that 
the expeller produces an oil of satisfactory quality for all industrial 
uses and is perfectly satisfactory for aeroplane lubrication. Evidence 
has been obtained that a good grade of No. 1 oil can be obtained by 
extraction with volatile solvent. Highly acid dark oil can be refined 
by alkali but not highly bleached, while low acid oils can be refined and 
_ bleached to almost water white. Attention is called to the varied 
uses made of the oil and the possibility of finding markets for the 
more sluggish No. 3 oil. 
O 
