FIXED VEGETABLE OILS.—Of these the most important is Olive Oil, procured from the ripe fruit of the olive (Olea Europaea, Linn.), which is cultivated for this purpose through all the countries of Southern Europe and Northern Africa. Its native country is Asia. On Lebanon and the Mount of Olives, and in the neighbourhood of Aleppo, the olive tree still grows wild. Its general diffusion through the countries suitable to its growth is no doubt attributable to the Romans, although the Carthaginians and others had previously procured and cultivated it. Pliny says (book xv., Bohn's edition), "Fenestella tells us that in the year of Rome 173, being the reign of Tarquinius Priscus, it did not exist in Italy, Spain, or Africa; whereas at the present day it has crossed the Alps even, and has been introduced into the provinces of Gaul and the middle of Spain. In the year of Rome 505, Appius Claudius, grandson of Appius Claudius Cæcus, and L. Junius, being consuls, 12 pounds of oil sold for an as; and at a later period, in the year 680, M. Seius, son of Lucius the curule ædile, regulated the price of oil at Rome, at the rate of 10 pounds for the as, for the whole year. A person will be the less surprised at this, when he learns that twenty-two years after, in the third consulship of Cn. Pompeius, Italy was able to export oil to the provinces." Its value has never decreased; and, next to corn, olive oil is still perhaps the greatest necessity of the nations of Southern Europe. It has been described as the cream and butter of Spain and Italy; and the quantity consumed in those countries as food, entering into their cookery in every imaginable way, is immense. There are several varieties in cultivation, which vary much in quality. That which yields the sweet Italian and French salad oils is the var. β. longifolia, Aiton. Its fruit, when pickled unripe, is also most highly prized. The inferior oils of Spain are made from the large olive, var. δ. latifolia, Aiton. In Italy and France the oil is obtained by crushing the fruit in mills,—the grinding stones of which are so set that they will thoroughly crush the pulpy part of the fruit without breaking the stone or kernel in the centre. The fruit, which is gathered for the purpose when very ripe, is not unlike a small damson in shape and colour, and the stone in the centre is very hard. After crushing in the mill, the pulp is put in bags made of rushes and slightly pressed, when the fine or virgin oil flows out abundantly. Afterwards the cake or marc is again broken up, mixed with water, and returned to the press, and an oil of an inferior quality is obtained. The cake or marc is once more broken up and mixed with water, after which it is placed in vats to ferment, and then again pressed. The result is an oil of a very inferior sort, only useful to the soap-makers. The oil of the olive is liquid at the ordinary temperature, but becomes solid a few degrees below 32°. In Spain the process is less carefully conducted. Instead of being gathered by hand, the olives are beaten from the trees, and are consequently much mixed—ripe, unripe, and decayed. They are left in large heaps on the ground to ferment, which partly breaks up the oil cells; they are then ground and pressed, and yield a very inferior oil. The finest virgin oil for table use is imported from Leghorn and from France. The common oil is chiefly used in England for dressing woolen cloths, for which purpose vast quantities are required in Yorkshire, the west of England, and other cloth districts. On the Continent it is also employed in making soap. In 1856 the imports were as follows:—From France, 358 tons; Portugal, 3175 tons; Spain, 2,301 tons; Sardinia, 907 tons; Tuscany, 1,973 tons; Two Sicilies, 6,093 tons; Turkey, 491 tons; Morocco, 2579 tons; Malta, 360 tons; Ionian Islands, 2900 tons; other parts, 278 tons; in all, 21,415 tons, or 5,595,580 gallons, valued at £1,124,755.
Palm Oil is obtained from the fruit of the oil palm (Elaeis Guineensis, Linn.), a native of Western Africa, by crushing the thin fleshy covering which surrounds the hard stone or seed, and by pouring boiling water upon the pulp, upon which the oil floats and is skimmed off. In this process, however, much of the colouring matter of the drupe, which is a fine orange-yellow, is retained, which, besides its colour, imparts to the oil a sweet violet odour. Palm oil, when imported, is of the consistency of butter. Vessels arrive entirely laden with it. It is put in casks of various sizes, but usually very large, and made to suit the stowage of the vessels. Spirits, tobacco, cutlery, cloths, beads, cowries, arms, gunpowder, and other articles, are given in barter to the natives in exchange for the oil. This trade has now obtained an immense importance, owing to the valuable discoveries by which the oil can be deprived of its colour, and a solid part, called palmitic acid, converted into candles of a very superior quality. The addition of sulphuric acid entirely carbonizes the yellow vegetable colouring matter. It is then submitted to the action of steam, at a temperature of 612°, in a still of peculiar construction, which carries over the particles of oil with the steam, leaving behind the charcoal or carbonized vegetable matter. Previous to the distillation, however, lime is added to neutralize the acid, and that also remains behind. The material which comes over runs from the still as a clear colourless oil, which upon cooling has the colour and consistency of lard in cold weather. This is cast into square cakes about 1½ inch in thickness, and 18 inches square. The cakes are placed between mats made of coir, or cocoa-nut fibre, and submitted to the action of powerful hydraulic presses, which force out the clain, a liquid about the colour and consistency of linseed oil. The mats are then taken from the press, and the cakes, which are now much harder, are remelted and made into candles. Nothing can give a better idea of the extent to which this manufacture is carried on than the fact, that Messrs Price and Co., at their works in London, and at Bromboro' Pool, Cheshire, are now making 150 tons of these candles per week, and give employment to upwards of 2000 persons. Great quantities are also consumed in the manufacture of soap. When it is remembered that each drupe will only yield about ¼ part of an ounce in weight, and that each palm only produces three or four pounds at one crop, the number of palms in the forests of Western Africa must be immense, and the industry called into action by this want of civilized man must exert a most beneficial influence over the destinies of the African races. The drupes are borne in immense clusters, each surrounded by sharp bracts, and they greatly resemble gigantic pine-apples both in shape and colour.
Cocoa-nut Oil is produced from the white kernel which lines the shell of the large cocoa-nut (Cocos nucifera, Linn., Nat. Ord. Palmae). This kernel is ground in mills in Ceylon, where it is largely cultivated for its oil; and when ground, the mass, called copperah, is submitted to considerable pressure. The oil runs at first limpid and liquid, but it afterwards becomes white and solid. It is largely used in making soap, and also in making candles; for the latter purpose the stearine oil is used. The oleine, both of cocoa oil and palm oil, is used for lubricating machinery. It is nearly all obtained from Ceylon, whence it is exported chiefly to this country in large casks and iron tanks.
Linseed Oil is pressed from the seed of the flax plant (Linum usitatissimum, Linn., Nat. Ord. Linaceæ). It is not imported very largely, being chiefly manufactured in this country from home-grown or imported seed. The seed is first ground in mills, and afterwards submitted to enormous hydraulic pressure. The oil yielded is of a dark brown colour, and is one of the best drying oils. It is therefore of great value to painters, who use this oil almost exclusively in mixing their paints. Linseed is imported in very large quantities from the East Indies, Russia, Germany, Holland, America, and other places. The total quantity received in 1856 was 1,150,150 quarters, valued at £3,195,634. This does not represent the value of the oil, for the cake or marc, which remains after the oil is expressed, is of considerable value for feeding cattle.
Seed Oil is a name applied to the expressed oil of the physic-nut (Jatropha curcas, Linn., Nat. Ord. Euphorbiaceæ). Within the last six years this oil has been brought into notice as a substitute for the dearer olive oil in dressing woolen fabrics. It has highly purgative properties; and the seeds imported, under the name of croton nuts, produced serious results
when first landed on the Liverpool quays; the tempting name induced many to eat their blandly flavoured white kernels, and the consequences were nearly fatal to some. The oil, too, at first produced disagreeable effects amongst the workmen, who have a habit of tasting with their fingers the various oils they use. This evil, however, soon cured itself, and the oil is now largely used. It is chiefly imported into Liverpool from Lisbon, but the Portuguese manufacturers obtain the seeds from the Cape de Verde Islands. There is no doubt that vast quantities might be obtained from the West Indies, where the plant is indigenous. It is cultivated in the East Indies, and its oil is called Bhoya Bhirindi til. The imports have reached nearly 400 tons per annum; but owing to the indefinite name given to it, this oil is confounded with others, and the exact quantity cannot be ascertained. The importers also have some interest in suppressing information respecting its source and true character. It is a good drying oil, and would probably, if boiled, be equal to linseed oil for painters' purposes.
Sesamum or Gingelly Oil is made from the seed of Sesamum orientale, Linn. (Nat. Ord. Pedaliaceae). This seed is grown extensively all through India, where its oil is known under various names, as Tillic Oil, Manchy noomer, Til ke tel, nullenai, tamool, &c. The seed is small, not much unlike the flax seed in shape: the colour usually a light drab—but there are dark-coloured varieties. The oil is bland and sweet, and useful for all purposes to which the common kinds of olive oil can be applied. In 1856, 5269 quarters of this seed were imported for expressing the oil; and of the oil itself in 1857, 42,136 gallons, or nearly 166 tons. The marc or oil-cake is much relished by cattle, and is very nutritious.
Niger-seed Oil is expressed from the seeds of Verbena sativa, H. K., or Guizotia oleifera, Cassini (Nat. Ord. Compositae), another East Indian seed, also extensively used in that country under the names of Ram til, Valisaloo Oil, Valisaloo noomer, &c. The seed only is imported here. It is black and shining, resembling in shape the common sunflower seed, but is scarcely larger than a caraway seed. The oil is as sweet and liquid as that of the olive, and answers the same purposes. About 700 quarters were imported in 1857.
Safflower-seed Oil is expressed from the seeds of the safflower plant (Carthamus tinctorius, Nat. Ord. Compositae), also a native of India, where it is very extensively cultivated, both for its flowers and seed. The latter are of the same shape and size as those of the sunflower, but are white instead of black. They yield a large quantity of a fine clear oil, of a peculiar golden-yellow colour. It has good drying properties, and burns well, but has a peculiar and not very agreeable odour. There is good reason for believing that this oil, known in India under the name of Kossum Oil, is the celebrated Macassar oil of the Malays, and, in all probability, of our own perfumers. It has certainly a specific effect upon the growth of the hair. The oil is not often imported, but a large quantity of the seed now finds its way annually to this country; but as the official designation of "seed unenumerated" is applied to this and many others in the returns, the exact quantity cannot be ascertained. Between 300 and 400 quarters were imported in 1857 into the port of Liverpool, and probably a much larger quantity into London.
Rape Oil is expressed from the seeds of Brassica rapa, and its variety B. oleifera, De Cand. (Nat. Ord. Cruciferae), a common European weed, which is, however, largely cultivated for its seed. It yields a yellowish-brown oil in considerable abundance, valuable for burning and other purposes. Several other cruciferous plants, yielding a similar oil, are also largely imported under the same name, and are consequently confounded with it. Thus we have immense quantities of the seed of Sinapis toria, S. glauca, S. nigra, sent from India under the name of rape-seed, and the colza or colza seed (Brassica campestris, var. oleifera, De Cand.) is imported from Holland and Germany, and finds its way into our markets under the same designation. The quantity of seed imported as rape in 1856 was as follows:—From Russia, 2556 qrs.; Denmark, 4402 qrs.; Germany, 2267 qrs.; Holland, 1850 qrs.; British East Indies, 251,890 qrs.; other parts, 1955 qrs.;—or 264,920 quarters in all, in which probably not more than 8000 quarters are genuine rape-seed. Besides the seed, a considerable quantity of the oil was imported from the continent of Europe.
Ground-nut Oil is yielded by the seeds of Arachis hypogaea, Linn. (Nat. Ord. Leguminosae).
The seeds are about the size of a small horse-bean, generally two in a pod. They are much used, when roasted, as food both in South America (its native country), and also in Africa, India, and China, in which countries it is now naturalized and grown to a great extent. The oil is thin and limpid, burns well, and is a good substitute for olive oil, both for the table and other purposes, as it is remarkably free from rancidity. It is almost pure elain, and has accordingly been recommended for watch and clock-work, and other delicate machinery. The quantity of the seeds imported in 1857 was about 2500 tons. Some small lots of the oil have also been imported, but the exact quantity cannot be ascertained. It is known in India under the name of Katchung Oil.
Caster Oil is expressed either with or without heat from the seeds of the palma-christi plant (Ricinus communis, Linn., Nat. Ord. Euphorbiaceae), a native of the East Indies, where it is known under many names. In Tanjore the native name of that which is obtained by putting the crushed seeds into hot water is Adivia aumedum. It is used for burning in lamps. That which is expressed without heat, and is consequently known here as cold-drawn, is there called Arandes ka tel. Only the cold-drawn is sent to this country, and it is nearly all used for medicinal purposes, in consequence of its valuable aperient qualities. It is now disseminated pretty generally through all tropical and subtropical countries. About 1200 quarters of the seed were imported in 1857, besides large quantities of the oil. Another seed is imported for the purgative oil which it yields, but the quantity is very small. It is the fruit of Croton Tiglium, Lam. (Nat. Ord. Euphorbiaceae), also a native of India; the oil is never used except for medicinal purposes. The seeds of Jatropha curcas, before-mentioned, are often imported as croton seeds, but not more than a few bushels of the real croton seeds are annually brought to this country.
Poppy-seed Oil, obtained from the seed of the white poppy (Papaver somniferum, Linn., Nat. Ord. Papaveraceae), is most likely of Asiatic origin. It is cultivated chiefly for its narcotic juice (opium), but the value of its seed for oil purposes is rapidly increasing; and the fact that it is easily cultivated in France and other temperate parts of Europe, adds much to its interest. Thousands of acres of land in France alone are now annually covered with crops of the white poppy, grown only for its seed, which yields a sweet limpid oil, esteemed by many as preferable for most purposes to that of the olive, especially as a salad oil. The impression which long prevailed, that the seed of a plant producing so poisonous a juice as that of the poppy could not be otherwise than injurious, actually led to legislative enactments against its introduction into France in former times. But, like those in our own country against logwood, they have long since passed away, and poppy oil and logwood are now amongst the most useful of our commercial materials. In 1856, 24,121 qrs. of this seed were imported, of which no less than 24,073 qrs. were from British India. The oil has not been imported, unless in very small quantities, from France.
Almond Oil is expressed from the kernel of the common almond (Amygdales communis, Linn.). The value of the sweet varieties for other purposes causes the small bitter almond to be generally used for expressing this oil, especially as the essential oil can afterwards be distilled from the marc. The fixed oil of almonds is chiefly manufactured in France; it is much used by perfumers, as it is very nearly inodorous, and will consequently receive the most delicate perfumes. It is an expensive oil, as it requires 1 ewt. of almonds to obtain 50 lbs. of oil. It is of a light yellow colour, and contains very little stearine, only about 24 per cent. It is often adulterated with the oil of Guizotia oleifera. Besides its chief use by the perfumers, it is also, to a small extent, used in the operations of pharmacy. The imports are small, and published returns contain both the fixed and volatile oils, consequently the exact quantity of each cannot be ascertained. Most of that used in Great Britain is home manufactured.
Amongst the less known oils and vegetable fats are the Madia Oil, yielded by the seed of Madia sativa, Molina (Nat. Ord. Compositae), a native of Chili, and cultivated in Italy for the sake of its oil, which is limpid and sweet. Gold of Pleasure Oil, from the seed of Camelina sativa, Cranby (Nat. Ord. Cruciferae), a native of the continent of Europe. It does not succeed well in England, but the oil is used for many purposes
on the Continent, being even employed in culinary preparations. Oil of Mexican poppy-seed (Argemone Mexicana, Linn., Nat. Ord. Papaveraceae) is a drying oil, and is used in Mexico, its native country, for polishing wood. It is also employed for various useful purposes in the East and West Indies, where it is now cultivated. Indian Almond Oil, a sweet limpid oil, is obtained from the kernels of Terminalia catappa, Linn. (Nat. Ord. Combretaceae). This tree is a native of India, and is now cultivated in the West Indies. The kernel is not very large, but closely resembles the almond in flavour. The oil has not yet been imported. Walnut Oil, expressed from the kernel of the common walnut (Juglans regia, Linn., Nat. Ord. Juglandaceae), is extensively manufactured in Circassia, where the tree is very abundant. It is used by the natives for almost every purpose to which oil is applied, but it is not exported.
The following liquid oils were exhibited in the Indian collection at the Exhibition of 1851, but no information given as to their uses or commercial value. Checonjee Oil, from the seeds of Buchanania latifolia, Roxb. (Nat. Ord. Anacardiaceae). Valuse nune, from the seeds of Guizotia abyssinica (Nat. Ord. Compositae). Poonseed Oil, expressed from the nuts of an unknown species of Calophyllum (Nat. Ord. Clusiaceae). Oondee Oil, from the nuts of Calophyllum inophyllum. Caju-apple Oil, from the cashew-nut, Anacardium occidentale, Linn. (Nat. Ord. Anacardiaceae). Neem Oil, obtained from the pulp of the marquis berries, or fruit of Melia azadirachta, Linn. (Nat. Ord. Meliaceae). Kurrunj Oil, expressed from the nut of Pongamia glabra. Ventonat (Nat. Ord. Leguminosae). Its chief value is in veterinary medicine. Country Walnut Oil, from the kernels of Alchornea triloba, Forst. (Nat. Ord. Euphorbiaceae). Country Walnut Oil, from the seeds of Berbera Königii, Roxb. (Nat. Ord. Aurantiacae). Hingun or Hingota Oil, from the seeds of Balanites Egyptiaca, Delile (Nat. Ord. Amyridaceae). Oil of Ben, from the seeds of Moringa pterygosperma, D. C. (Nat. Ord. Moringaceae). Mooneela Grain Oil, from the grain of Dolichos biflorus, Linn. (Nat. Ord. Leguminosae).