ce between this oil and
rape oil in composition.
_The Fatty Acids._--The acids produced by adding HCl to the potash
soap were almost entirely insoluble in water. The actual amount of
potash required to neutralize the acid in the wash water equaled 0.20
per cent. of the oil originally taken.
The insoluble fatty acid amounted to 95.315 per cent. of the oil
taken. It was evidently a mixture of two or more fatty acids. On
trying to take its melting point, I found that it commenced to soften
at 17 deg. C., was distinctly liquid at 19 deg., but not completely
melted until 22 deg. C.
According to O. Bach (Year Book Pharm., 1884, p. 250), the fatty acids
from rape seed oil melt at 20.7 deg. C., which is fairly concordant with
the result obtained for cabbage oil acids.
The neutralizing power of these acids was then tested. 0.698 gramme
dissolved in alcohol required 20.52 c.c. decinormal alkali. It is a
singular coincidence that brassic acid (C_{22}H_{42}O_{2}), which is a
characteristic acid of colza and rape oils, would have required almost
exactly this quantity of alkali for neutralization, 0.698 brassic
acid theoretically saturating 20.69 c.c. of decinormal alkali. I
am disposed to regard this as a coincidence, since a subsequent
experiment showed that the lead salts formed were partially soluble in
ether, whereas the lead salt of brassic acid is said to be insoluble
in this liquid.
WOOD OIL (_Elaeococcus cordata_).
_Appearance, etc._--This oil has a decided brown color and a
persistent and disagreeable odor. It is rather more fluid than castor
oil. Glass vessels containing it soon show a film of apparently
resinous material, which forms whenever a portion of the oil flows
from the lip or edge down the outside of the vessel, and is thus
exposed to the air in a thin stream. This drying power is one of its
most prominent characters. If a few drops be exposed in a flat dish,
in the water oven, the oil dries rapidly, so that in two hours the
gain in weight will be appreciable, and in four hours the whole will
have become solid.
_The Specific Gravity at 60 deg. Fahr._, 940.15.--This is an unusually
high gravity for a fixed oil. The only two which exceed it are castor
oil, which is 960, about, and croton oil, which is very similar to
this, 942 to 943 (A. H. Allen). It is interesting to note that both
these oils are yielded by plants of the natural order _Euphorbiaceae_,
to which the plant yielding so-called wood
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