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.
Oil Palm (Elaeis Guineensis).
Oil Palm. - Part of Female Flower Spike, Fruit, and Nut with and without envelope.