By S.S. BRADFORD, Ph.G.
Having had occasion during the last six years to manufacture lead
plaster in considerable quantities, it occurred to me that cotton seed
oil might be used instead of olive oil, at less expense, and with as
good results. The making of this plaster with cotton seed oil has been
questioned, as, according to some authorities, the product is not of
good consistence, and is apt to be soft, sticky, and dark colored;
but in my experience such is not the case. If the U. S. P. process is
followed in making this plaster, substituting for the olive oil cotton
seed oil, and instead of one half-pint of boiling water one and one-half
pint are added, the product obtained will be equally as good as that
from olive oil. My results with this oil in making lead plaster led me
to try it in making the different liniments of the Pharmacopoeia, with
the following results:
_Linimentum Ammoniæ_.--This liniment, made with cotton seed oil, is of
much better consistency than when made with olive oil. It is not so
thick, will pour easily out of the bottle, and if the ammonia used is of
proper strength, will make a perfect liniment.
_Linimentum Calcis_.--Cotton seed oil is not at all adapted to making
this liniment. It does not readily saponify, separates quickly, and it
is almost impossible to unite when separated.
_Linimentum Camphoræ_.--Cotton seed oil is far superior to olive oil in
making this liniment, it being a much better solvent of camphor. It has
not that disagreeable odor so commonly found in the liniment.
_Linimentum Chloroformi_.--Cotton seed oil being very soluble in
chloroform, the liniment made with it leaves nothing to be desired.
_Linimentum Plumbi Subacetatis_.--When liq. plumbi subacet. is mixed
with cotton seed oil and allowed to stand for some time the oil assumes
a reddish color similar to that of freshly made tincture of myrrh. When
the liquor is mixed with olive oil, if the oil be pure, no such change
takes place. Noticing this change, it occurred to me that this would be
a simple and easy way to detect cotton seed oil when mixed with olive
oil. This change usually takes place after standing from twelve to
twenty-four hours. It is easily detected in mixtures containing five
per cent., or even less, of the oils, and I am convinced, after making
numerous experiments with different oils, that it is peculiar to cotton
seed oil.--_American Journal of Pharmacy_.
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