e. In
this way it was found that the oleic acid obtained from the ethereal
solution of the lead salt amounted to 83.15 per cent. of the oil.
This acid was proved to be oleic, by its saturating power and its
melting point, which were fairly concordant with those of the pure
acid.
CABBAGE OIL (_Brassica, sp._).
_Appearance, etc._--The sample was of a deep brown color, of a
fluidity intermediate between olive and castor oil, and possessed a
strong, rather disagreeable odor.
_The Specific Gravity at 60 deg. Fahr._, 914.0.--The specific gravity of
rape oil and colza oil, both of which are obtained from species of the
genius _Brassica_, varies from 913.6 to 916.
_Exposure to Cold._--This oil by exposure to a temperature of -12 deg.
C. (10 deg. F.) becomes solidified in course of an hour, a bright
orange-yellow mass resulting.
_Qualitative Examination._--The three reagents before indicated were
applied to this oil.
_(a.) Sulphuric Acid._--The color produced was very marked and
characteristic; it differed considerably from any of the others
simultaneously tested, the nearest to it being olive end rape oil.
_(b.) Strong Nitric Acid._--The reaction was more violent than before,
the stratum of oil after cooling being darker in color than in the
three cases before mentioned. The reaction with rape oil was similar
in all respects.
_(c.) Elaidin Test._--The solid mass of elaidin formed was of a darker
color than that from olive, almond, and tea oil, but closely resembled
that from rape oil.
_Free Acidity._--This was estimated as above described. 100 grammes of
oil would require 0.125 gramme caustic potash. The samples of rape oil
examined by Deering (loc. cit.) were found to require from 0.21 to
0.78 KOH per 100 grammes oil.
_Saponification of the Oil._--Upon saponifying with alcoholic potash,
it was found that 1,000 grammes of oil required 175.2 grammes of
potash for complete saponification.
The number obtained by Koettstorfer for colza was 178.7, by Messrs.
Stoddart for rape oil, 175-179, and by Deering for rape oil,
170.8-175.5. The only other oil of which I can find figures resembling
these is castor oil, which requires 176-178 grammes per kilo (Messrs.
Stoddart). The difference in specific gravity between this (cabbage)
oil and castor oil and the solubility of the latter in alcohol point
to a wide distinction between them. Hence I think the numbers above
given conclusively demonstrate the resemblan
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