2,1 sort gingelly oil, in commerce erroneously called rape (h.horasanee yclloo), is expressed from a variety of sesamum, and differs but little from the one above mentioned.
Sinapis species, mustard oil—Rai ka tol, I iIND. ; Kada gboo yennai, TAM. ; Avaloo noona, Sarsava I1001111, TEL. Five or six species of Sinapis are cultivated in all parts of India, for the sake of the oils they yield ; those most frequently seen are S. glance, S. toria, and S. TACCRIOSA. Tho seeds of the Sinapis alba yield by expression 36 per cent. of a bright yellow, pleasant-tasted, edible oil, having a strong smell and slight taste of mustard. The seeds of Sinapis nigra yield only 23 per cent. of an oil in all respects similar to the above.
Sterculm betide., fetid sterculia oil—Coodira pasjnn yennal, TAM. This semi-solid oil is obtained by ex pression from the seeds of a large forest tree.
Strychnos nux vomica, Nux vomica oil—Carunjooty, CAN. ; Mooyettio cottay yennai, Ta3r. An empy reumatie oil prepared from the fresh nut, is used medicinally by native practitioners.
Tcrminalia bellerica, Belleric myrobalan oil—Tanikai yennai, TAM. A medicinal oil obtainable in small quantities from the kernel of the Belleric myro balan ; the drupo is used as a tanning material., Terininalia catappa, Willd., Indian almond oil, the pro duct of this species of Terminalia.
Tcrminalia chebula, Chebulie myrobalan oil. A medi cinal oil procurable in very small quantities from the kernel.
Thespesia populnea, Portia nut oil — Pares pipul, IliND. ; Poorasam yenned, TAM. This deep, red coloured, and somewhat thick oil, is obtained from the seeds of this tree, which grows in great abund ance in the Peninsula. It is extensively planted as an avenue tree, for which its quick growth and the beauty of its flowers render it a favourite. The wood is used for boat-building and cabinet work.
Thevetia neriifolia, the `exile' oil. The kernels of the seeds of this common shrub yield by expression a clear bright yellow-coloured oil.
Vateria Indies, piney tallow or doopada oil — Piney yennai, TAM. This valuable tree, besides its oil, yields a resin nearly equal to copal. It grows plentifully in the jungles of the western coast. The oil is perfectly solid, even in hot climates, and is prepared by cleaning the seeds, then roasting and grinding them into a mass. To 5 seers of seed add 12 seers of water, and boil until the oil rises to the surface. Remove the oil, stir the con tents of the vessel, and allow it to stand until the following day, when more oil will be observed on the surface, which may be collected, and the process L repeated. The oil is principally used for lamps, but is very suitable for soaps and candle-making.
r Wrightia antidysenterica, rosebay oil—Vaipallay yen ri TAM. A thick, scarlet-coloured, medicinal ' oil, partaking doubtless of the properties of the seed.
Oil manufacture, in British India, by means of the Kolhoo or oil press, is a wasteful pro cess, in so far as there is no press or other contrivance employed to squeeze out residue of oil from the cake ; and illustrative of the imperfect manner in which the oil is separated from the seeds, it may be mentioned that while a com mon pressman only obtained some GI per cent.,
Boussingault, in his Laboratory, from the same seeds actually procured 41 per cent. When the oil-cakes are meant for feeding stock, such loss is of little consequence, inasmuch as the oil serves a very good purpose ; but when the cake is only intended to be used as a manure, it is a great loss, inasmuch as the oil is of little or no use in adding any food for crops to the soil. In Europe, to crack the shells of the hard seeds of lint and rape, they aro passed between cast-iron rollers, which can be set at varying distances apart according to the size and hardness of the seeds. Rollers do their work rapidly, but they require great power to work them. In sonic places vertical mill stones or runners are used, while in others the hard seeds are passed between tho rollers on to the runners. When the seed is sufficiently bruised by either or both of these means, it is collected into hair bags and placed in a wedge-press. In olive oil mills a screw press may be used, but the hardness and smoothness of the grains of lint and rape, and the cavities formed by the broken shell, which retain the oil, require the exertion of a stronger force. The hair bags containing the crushed seeds aro placed between wedges of wood contained within a strong framing. The wedges are then driven down by a heavy rain or pestle worked by machinery until the pestle rebounds from them three times, when they are judged to be sufficiently tight. The oil thus obtained is of the best quality, and is kept distinct from that obtained by the after-process. The seeds come out of the bags in the form of flat cakes ; these are broken up, and pounded in mortars with heavy stampers, which reduce the parenchyma of the seed to a fine meal, so that the oil can escape more freely when subjected to a second compres sion, which is now aided by heat. The pounded seed or meal is heated in a pan, to the temperature of melting beeswax, and is kept in agitation by a spatula worked by machinery. The meal is again put into hair bags and compressed, and the resulting oil is considered to be the best of the second quality. Another compression produces oil of the ordinary second quality. During the heat ing of the meal a little water is sometimes added, but in Holland this practice is considered to be injurious. The cakes are still fat and soft, and are sold as food for cattle ; but the Dutch break them down and stamp them again. The result is an impalpable paste, which is hard with a very little water, and kept for some time at the tem perature of boiling water, with diligent stirring. It is then subjected to the greatest pressure that has yet been applied, and the result is an oil of the lowest quality. The cake is dry and hard like a board, and is used for manure. Some of the small millers in Holland purchase oil-cakes from France and Flanders for the purpose of pre paring this inferior oil.