seeds of the tobacco-plant (see Narcotics—Tobacco, p. 1325) contain about 30 per cent. of a fatty oil, which is extracted by powdering them, kneading them into a stiff paste with hot water, and pressing hot. The oil is clear, limpid, golden-yellow in colour, inodorous, and mild-flavoured ; its density is 0.923 at 15° (59° F.); it remains liquid at — 15° (6° F.), dissolves in 168 parts of alcohol at 0.811 sp. gr., and saponifies readily. One authority excludes it from the drying oils ; another considers its drying quality to be unusually developed, and recommends it for paints and varnishes.
frnit-pulp of the tucum, aouara, or kiourou (Astrocaryum vulgare), of Brazil and Guiana, yields an oil used for many different purposes. The palm is more important perhaps as a fibre-yielder (see Fibrous Subatances—Astrocarywn, p. 920).
or fatty oil is a product of the so-called " oil-tree " of China, Cochin China, and Japan (Aleurites cordata [Elcsococca vernicia, Dryandra cordata]), and must not he confounded with the Malayan article, which is an oleo-resin (see Resinous Substances Gurjun). The fruit capsules of the t'wng are filled with rich oil-yielding kernels, from which 35 per cent. by weight of oil may be obtained by simple pressure in the cold. The sp. gr. of the oil is at 15° (59° F.). It possesses several remarkable properties: heated to 100°-200° (212° 392° F.) out of contact with the air, it retains its original limpidity after cooling, but in contact with the air, it solidifies almost instantaneously, melting again at 34° (93° F.), and exhibiting the same elementary composition ; the cold-expressed oil rapidly solidifies by light in the absence of air ; and its drying qualities exceed those of any other known oil. It is devoid of colour, odour, and flavour. The oil is produced in immense quantities in China ; in the provinces of Ichang and Szechuen, it is one of the principal articles of native manufacture, and its importance in local commerce is shown by the following statistics :—Hankow, the chief market for the export trade, exported 336,053 piculs (of 133i lb.) in 1878, and 203,820i piculs, value 317,548/., in 1879 ; Shanghai imported 69,223/ piculs, and exported 31,4921, in 1879 ; Chefoo imported 4011 piculs in 1878, and 2847 in 1879 ; Chinkiang imported 184,442 piculs in 1878, and 117,082 in 1879 ; Ningpo imported 29,652 piculs in 1878, and 13,915 in 1879; Wuhu imported 11,916/ piculs in 1878, and 6695 in 1879, in foreign craft, and, in the latter year, a quantity estimated at 3711 tons in native craft. In China, the oil is universally employed for caulking and painting junks and boats, and for varnishing and preserving woodwork of all kinds ; also for lighting, though considered inferior to Camellia-oil (see Tea-oil) for this purpose, and in medicine. The oil is unknown to European commerce, but an attempt to naturalize the tree in Algeria has been projected. Its industrial value has been too long neglected.
Vegetable Tallow (Fa. Suif d'arbre).—At least two vegetable fatty substances are known by the name of " vegetable tallow." (a) Chinesc.—The vegetable tallow of China is produced by the " tallow-tree " (Stillingia [Croton, Sapium, Exccecaria] sebifera). It is a native of China and the adjacent islands, and has been introduced and naturalized in India and the warmer parts of America. In China, it is chiefly
cultivated in the province of Chekiang, and the adjacent Chusan Archipelago, in Kiangse, and in Hoopih. In India, it thrives in the N.-W. Provinces and the Punjab, especially at Paonee, in Gurhwal ; at Ayar Tali and Hawul Baugh, in Kumaon ; and in the Kangra Valley. The tree flourishes equally well on low alluvial plains, in the rich mould of canals, in sandy soils, and on mountain slopes. Its fruits are about i in. in diameter, and contain 3 seeds, thickly coated with a fatty substance, whence the " tallow " is obtained. The ripe fruits are gathered at the commencement of the cold weather, November-December, when all the leaves have fallen, by means of a sharp crescent knife, attached to a long pole. The seeds are first picked from the stalks, and bruised in a mortar to loosen the shells, which are sifted away. The clean seeds iu their fatty envelope are next placed in a wooden cylinder, open at the top, and with convex open wickerwork bottom, suspended within iron dishes 6-8 in. deep, containing water which is made to boil ; the seeds are thus steamed for 10-15 minutes, when they are removed, and mashed in large mortars, and thence transferred to bamboo sieves, kept at a uniform temperature by means of live ashes. The tallow separates, and escapes through the sieves, forming a solid mass. (The seeds are usually passed through the steaming and straining processes a second time. Finally the seeds are themselves treated for their oil, as will be described presently.) The tallow now resembles coarse linseed meal, its brown colour arising from the thin skin between the seed and the tallow, which is separated by pounding and sifting. The tallow is next put between circles of twisted straw, 5-6 of which, laid upon each other, form a hollow cylinder, bound with bamboo hoops 3 in. wide. The straw cylinders when filled are placed in a rude press with their hoops attached. The tallow is forced out in a liquid state, and is collected in receptacles, where it solidifies on cooling. It is again melted, and poured into moulding-tubs, sprinkled inside with dried red earth, to prevent adhesion. When cold, it is turned out in masses of 80 lb., a hard, brittle, pure opaque white, tasteless and odourless fat. Its melting-point varies from 37° to 44° (94°-1114° F.), and its composition is almost pure stearine. The yield is about 20-30 per cent. of the weight of the seeds. Its chief and almost only application in China is for making candles, which are usually coated with wax ; in India, it has been tried as a lubricator ; and it is found to burn well, without smoke or smell. An immense native trade is carried on in it in China. Hankow exported 89,269 piculs (of 133* lb.) in 1878, and 90,413i piculs, 229,0991., in 1879; Shanghai imported 46,611i piculs, and exported 60031, in 1879 ; Chinkiang imported 44,987 piculs in 1878, and 42,943 in 1879; lchang exported 843 piculs, 1119/., in 1878, and 657i piculs, 996/., in 1879; Kiukiang exported 6207 piculs, in 1878, and 4559 piculs in 1879; Wenchow exported 69 piculs, 416/., in 1878, and 2901 piculs in 1879 ; Wuhu imported 4814* piculs in 1878, and 4287i in 1879.