In the Central and Eastern Provinces “hard” oil is the commercial name applied to the kind which is generally made. At Onitsha the natives may be seen bringing in this oil, which is of such a consistency that even at an atmospheric temperature of 90° it remains in a solid wax-like condition. The earthen vessels in which such oil is conveyed to the factories, when accidentally dropped and broken, do not necessarily occasion the loss of any oil. The thickened condition is entirely due to the method of preparation, during which important chemical changes occur, which appear to be detrimental to the oil for some of its most important uses, especially that of soap manufacture, while rendering it suitable for employment for making candles. The important difference in the preparation of this oil lies in the fact that instead of the fresh fruits being used, the pericarp is separated from the nuts by means of partial decomposition, induced by burying the fruits in the ground for a period varying from three weeks to two months. The semi-decomposed pericarp is then easily removed by pounding or treading out in a canoe-shaped receptacle, after which the fibrous mass is boiled, and the liquid oil is skimmed and allowed to set in earthen jars, in which it is carried for sale to the factories.
The extraction of kernels from the nuts is one of the usual occupations of the women and children of a village, when not assisting in the preparation of oil. The nuts are spread in the sun for about a week or more until a shrinkage of the kernel occurs, which renders the nut-shell capable of being easily cracked without damage to the interior. It is said that in the Jebu district, to the north-east of Lagos, the local price paid for kernels ranges from 4d. to 4½d. for a filled tin bowl having the diameter of nine inches.
The primitive method of extracting kernels, by means of cracking the nut-shell between stones and picking out the contents, has not yet given way to the employment of the various machines which have been introduced from time to time to supersede it.
A black oil is extracted at Oshogbo by roasting the kernels in an earthen pot until black, and stirring meanwhile until the whole mass becomes covered with exuded oil. A small quantity of cold water is then sprinkled into the pot after removing it from the fire, and the contents are pounded in a mortar until an oily meal is produced. This is boiled, and, when the mixture is cool, the oil is skimmed from the surface of the water which has been added for the boiling. This oil is apparently only used locally.
The existing native social system, under which the male head of a family receives almost exclusive consideration, is opposed to native co-operation in any mechanical process, whereby a relief from labour of his numerous dependants—wives, children, and aged or infirm relatives—would be incurred at the expense of his enhanced personal labour; he being the carrier and disposer of the produce at the market. By the conveyance and sale of nuts instead of kernels, a much smaller return in value would be obtained for the same weight of material, i.e. a similar amount of personal energy. The dependants, incapable of assisting in transporting, would remain idle, unless some similar work could be found for them. Up to a short distance from the delivery point (which would determine itself) the nuts instead of the kernels would be brought in for sale, and, limited by the capabilities of the available palm-tree climbers, the family dependants would be able to prepare larger quantities of pericarp oil; but the increased accumulation of kernels would further decrease the radius from the selling centre at which the carriers would be able to work.
If the entire fruit were to be bought up for mechanical extraction of pericarp oil as well as kernels, the carrying labour would be still further enhanced, and the work of the oil-manufacturing communities would resolve itself into three operations—viz. climbing trees, chopping out fruit, and transporting—which would mean the exclusion from work of all but the strong adults, or the reduction of workers by 30 to 50 per cent. perhaps. The number of skilled palm-tree climbers is said to be decreasing in many districts, and, owing to the sparsity of the population in some localities, a very large proportion of the annual yield of fruit remains unharvested.
The investigation of the several varieties of the oil palm of the country is in progress at the Imperial Institute, and the characters of the most important are now well known, and may be compared here with the varieties from the Gold Coast, Sierra Leone, Gambia, and Northern Nigeria. The typical form, which, although subject to some variation, possesses certain marked characteristics, may be said to fall under the following general description:
Fruiting heads generally large. Fruit large, orange to scarlet in colour, with a variable amount of purplish black suffusion at the apex, which may extend over more than half of the fruit or may be altogether absent. Pericarp thin, kernel large with a thick shell. Names: “Ope yope” or “Ope pankora” (Yoruba), “Ok-poruk-pu” (Ibo), “Udin” (Beni), “Ak-porro-jub” (Efik), “Irök-Eyop” (Ibibio), “Abe pa” and perhaps “Abe dam” (Fanti, Gold Coast), “Tug bore” (Mendi, Sierra Leone), “Tabel-tiloli” (Timani, Sierra Leone), “Tengo” (Mandingo, Gambia), “Kabe-kalako” (Jolah, Gambia), “Neul” (Joloff, Gambia), “Qua-qua” (Haussa, N. Nigeria), “Yi-ku-niche” (Nupe, N. Nigeria). Only the typical form has as yet been observed in Sierra Leone, Gambia, and Northern Nigeria.
The other particularly important variety is that commonly referred to as the “soft-shelled” or “thin-shelled” palm fruit, which has been recorded from many localities in West Africa. The following description will include the forms contained in this group:
Fruiting heads often large. Fruits large or small, generally the latter, dark coloured. Pericarp thick, kernel rather small, with a thin shell. Names: “Ope-Arunfo” (Yoruba), “Au-su-ku” (Ibo), “Ivioronmila” (Beni), “Asoge-e-jub” (Efik), “Eduege Eyop” (Ibibio), “Abe-bobe” (Fanti, Gold Coast).