Palm-nut-, Palm-kernel-, or Palm-nut-kernel-oil.---This oil, which is known in com merce under each of the synonyms given, is extracted from the nuts or kernels of the fruit described under Palm-oil. Some 10-12 years ago, the nuts were partly charred, and the oil that ran from them, discoloured by the burnt cellulose, was exported either separately or mixed with palm-oil. This brownish oil could only be very slightly bleached, and was therefore not of great value for soap-making. Since the improved methods of oil extraction (see p. 1451) have been worked out, the nuts have been exported to England, and the nearly colourless oil there extracted, while the ground nuts have been used for cattle-food. The following is a description of the old process, which is still in vogue in some districts.
The nuts which have been subjected to the processes described for making oil are deprived of their external pulp, and the kernels only remain ; or old nuts are picked up from under the trees, and put in the sun for days, and even months, until they are perfectly dry. They are then broken between two stones, and the kernels are obtained whole, in perfect condition, and fit for exportation, and so form the commercial palm-kernels. If they have not been perfectly dried, the kernels break into pieces. The oil obtained from these kernels by the following process is called "white-kernel-oil." They are placed in wooden mortars, and pounded very finely ; then removed to a grinding-stone, and ground into a homogeneous mass, which is put into cold water, and stirred with the band. The oil rises in white lumps on the surface of the water, and is collected and boiled. It is of a very light straw-colour, and, when exposed to the sun and dew, becomes, after a time, perfectly white. " Brown " or " black " oil is thus obtained. The kernels are put into /* pan, and fried ; the oil oozes out, and is strained ; the fried nuts are placed in wooden mortars, pounded, and afterwards finely ground on a grinding-stone. The mass is thrown into a small quantity of boiling water, and stirred constantly ; the oil rises, and is continually skimmed off. The pulpy mass is removed from the fire, spread out in a large bowl, and allowed to coo], after which it is again ground, and put by until the cool of the day, when it is mixed with a little water to soften it. It is now beaten with the hand for some time until the oil comes out in white pellets.
As soon as this is observed, a large quantity of water is put into it, and a fatty substance floats on the top ; this is skimmed off and boiled, and the pure oil is obtained.
By whichever of these processes it is obtained, the oil, when freed from impurities, is of a pale primrose-yellow colour, with a characteristic odour not unlike that of coco-nut-oil, which it strongly resembles in its chemical and physical characteristics. Indeed, for soap-making, it has largely sup planted coco-nut-oil in the cheaper soaps in which that has hitherto been employed on a large scale. (See Coco-nut-oil ; Soap.) It is slightly softer than good coco-nut-oil, its fusing-point being tolerably constant at (78° F.). If, however, the whole of the oil be removed from the kernels (by a suitable solvent), the resulting meal is not so fattening for cattle, but the oil is slightly harder, containing a larger proportion of the higher terms of the series, lauric (or lauro-stearic) acid, cocinic acid, &c. The nil itself, being tolerably pure, is a neutral glyceride, and does not readily get rancid. Its fatty acids, however, are partly fixed and partly volatile, like those of coco-nut-oil.
Phulwara-oil.—The phulwara or "Indian butter-tree" (Bassia butyracea) is a native of Nepal and the Almorah Hills, ranging between 1500 and 4500 ft. in elevation. The seeds or kernels, having the appearance of blanched almonds, are bruised to the consistence of a fine pulp, which is placed in cloth bags, and left under a moderate weight until the oil has escaped. The latter immediately assumes the consistence of hogs' lard, and remains in this semi-solid condition in the ordinary temperature of the plains of India, say 35° (95° F.), but melts completely at 49° (120° F.). It has a delicate white colour, keeps for many months in India without exhibiting any unpleasant flavour or odour, and is soluble in warm alcohol. Locally, it is extensively used as a medicinal applica tion, as a perfumed ointment, and as an adulterant of ghee (clarified animal butter). It makes an excellent soap, burns in lamps with a bright flame free from smoke and smell, and is suitable for candle-manufacture. The refuse cake after extraction of the oil is eaten by the Indian poor. For oils yielded by other species of Bassia, see Illipi-butter (p. 1392), Mahwa-oil (p. 1394), and Shea butter (p. 1410).