ON RICINOLEIC ACID. 
241 
The atomic weight of the anhydrous ricinoleic acid, found 
by calculation, is 3616.2, which differs somewhat from the 
directly determined number, but not more than is frequently 
the case in compounds which possess a high atomic weight, 
The ready solubility of the ricinoleate of baryta in hot, and 
the sparing solubility in cold alcohol, especially favors the 
separation of this acid from those simultaneously formed in 
the saponification of the castor oil, as only one-third per 
cent, of this salt dissolves in cold alcohol of 0.S15 specific 
gravity, and it crystallizes from the hot alcoholic solution 
on cooling in laminar crystals. When the baryta sait of an 
impure acid (altered by exposure to the air) is treated with 
alcohol, a large quantity remains dissolved in the cold alco- 
hol. Both the free acid, as well as its salts, dissolved in 
alcohol, experience a change by exposure to the atmosphere 
other acids being produced. This behaviour is peculiar to 
most of the fatty acids when exposed for any length of time 
to the influence of oxygen, especially in the fluid state. 
The salts of lime and lead are also very readily soluble 
in hot alcohol ; but their solubility at different temperatures 
does not vary very much, especially the lime salt, so that 
this is not so well adapted as the baryta salt for studying 
the acid. 
The affinity of this acid with Gottlieb's pure oleic acid 
is worthy of attention ; it is such that these two acids might 
be regarded as differing solely in the number of the atoms 
of oxygen, the hydro-carbon radical being the same. 
Pure ricinoleic acid, separated from its baryta salt by 
muriatic acid, is a very weak acid, the alcoholic solution of 
which faintly reddens blue litmus paper. It solidifies at 
about 32°. — Journ.fur Prakt. Chem. and Chem. Gaz. 
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