Palm Oil, a fatty oil of the consistence of butter, of a rich orange color, sweetish taste, and odor like that of violets or orris root.
It is the product of the fibrous fleshy coat of the drupe or stone
fruit of the palm known as the elms Guineensis of W. Africa, belonging
to the tribe of cocoanut palms. The same oil is also obtained in Brazil, Cayenne, and the West Indies, and is probably yielded by other species
of palm besides that named. To obtain it, the negroes bruise the fruit
and cover it with boiling water, upon which the oil rises and is skimmed
from the surface. It retains the coloring matter of the fruit, which is
removed in the subsequent treatment of the oil in the English
factories, either by bleaching
in shallow vats on the surface of hot water or by various chemical
methods of treatment. Each drupe affording only about 1/16 of an ounce
of oil, and each tree only 3 or 4 lbs. of it, an immense amount of labor
must be expended in securing this product, and the forests of palm must
be of great extent. The nuts were formerly rejected, but a clear limpid
oil is now obtained from them, called palm-nut oil. - Palm oil is very
extensively used in the manufacture of candles and soap, and in the
various kinds of axle grease.
It melts to a very thin fluid at temperatures varying from 75° to 95°
F.; the older it is, the greater is the heat required to melt it. By
age and exposure it becomes rancid and whitish. In ether it is perfectly
soluble,
slightly so in cold alcohol, and in boiling alcohol dissolves readily,
but separates on cooling. It consists of margarine, oleine, and a solid
fat resembling stearine and called pal-mitine, which constitutes about
two thirds of its weight. This substance is further reduced to palmitic acid and oxide of glycerine.
The change takes place in saponification; and as these ingredients also
exist uncombined in the commercial oil, this is in better condition
than any other oil for the process
of soap making. In the manufacture of candles, the oil, having been
melted by steam pipes introduced into the casks, and freed from
impurities, is mixed with one seventh to one sixth of its weight of sulphuric acid, and is briskly agitated for about two hours in copper
boilers heated by steam to about 350°. The glycerine and sulphuric acid
by their mutual reaction are thus decomposed and escape partially in
carbonic and sulphurous acids, and the remainder by subsequent washing.
The impure acids are next distilled in copper stills heated by steam
injected at a temperature of 600°. The dark residue in the retorts is
made by pressure to yield further portions of oil at the close of the distillation,
and the black solid mass which remains is used for fuel. The distilled
fat, when cooled to 50° or 54°, is broken into cakes 18 in. square and
about 1 3/4 thick, which are distributed upon squares of coir or
cocoanut matting, and these being piled upon each other are submitted to
the action of a hydraulic
press at a temperature of 75°. The fat thus obtained may be run at once
into candles for the European markets; but for tropical climates it is again submitted to pressure at a temperature of 120°. The soaps made with palm oil retain the natural agreeable odor of the oil. - In Africa palm oil is eaten to some extent by the natives as a sort of butter. In medicine
it is recognized as an emollient, and employed sometimes in friction or
embrocation, though possessing no specific virtue over other oleaginous
substances.
