Oilseed

“ Linseed Oil. The seed of the flax plant which is extensively grown in North Dakota, Argentine Republic and Russia, contains approximately 36% of oil which may be obtained by grinding, heating, and expression. Ripe native seed generally produces [2] a pale oil of little odor; the oil from Argentine seed often having a greenish tint and an odor resembling sorghum. While filtering, pressing and ageing will remove considerable of the (“foots”) mucilaginous matter, phosphates, silica, etc., from the oil, the better grades which are intended for varnish making are often refined with sulphuric acid. ”

“ The Fat Oil of Plants is particularly found in kernels, seeds, and some fruits; some kernels contain such a vast quantity thereof, that, on being very slightly bruised in a mortar, they discharge it in great abundance. Sweet and bitter Almonds, Walnuts, and Lint-seed, are all of this kind; and require no other management but to be pounded and pressed, to make them yield a great deal of Oil. But there are others more meagre, that being ground produce an almost dry flower. ”

“ Oil Seeds.—The seeds of a great variety of plants, such as the flax, hemp, rape, mustard, cotton, and sunflower, are exceedingly rich in oil, some of them containing nearly half their weight of that substance. Of these oil-seeds there are many which might with advantage be employed as fattening, food, although one only—linseed—has come into general use for that purpose. ”

“ It sometimes happens that different parts of the same plant contain different oils; the orange, for example, furnishes three different oils, one of which resides in the flowers, another in the leaves, and a third in the skin or epidermis of the fruit. The quantity of oil varies not only with the species, but also in the same plant, with the soil, and especially the climate; thus in hot countries it is generated most profusely. ”

“ It is a mistake to suppose that the seeds are the only parts of the plant that contain oil. It is found in all parts of vegetable substances, but is usually concentrated in the seed. It is rather an interesting fact to know that in the seeds of plants both the protein and fats or oils are found, as a rule, in a highly concentrated state, while the carbohydrates are not found chiefly in the seed itself, that is the germ, but distributed in the fleshy envelope surrounding it or in roots or tubers. ”

“ A second error, too, is the supposition that the oil increases proportionally to the flesh of the berry, it being the fact that the oil is all the time undergoing a change into flesh, and the stone is growing larger and larger within. It is for this reason more particularly, that care is taken to water the tree at this period; the real result of all this care and attention, as well as of the fall of copious rains, being, that the oil in reality is absorbed as the berry increases in size, unless fine dry weather should happen to set in, which naturally tends to contract the volume of the fruit. ”

“ The best seed is generally preserved for sowing, and the second sort yields considerable profit in the oil which is obtained from it by pressure. This, which is called linseed oil, is equally useful in the arts and in medicine. It is occasionally employed for making the soap called green soap. If heat be applied during the pressure of the seeds, the oil attains a yellowish colour and a peculiar smell, and, in this state, it is used by painters and varnishers. An infusion of the seed, in the manner of tea, is recommended in coughs ”

“ There are many other adulterants which are used in unison with cotton seed oil, such as sesame, palm nuts, hemp, cupra or sunflower, and a host of others of strange origin. It is not safe to say that these supposititious comestibles are always innocuous. Many an oil retains the subtle qualities of the plant which produced it, and it may be that obscure maladies which puzzle the doctor are not unfrequently caused by the detestable practice of supplying for the genuine article something which looks sufficiently like it to mislead, and, it may be, poison the hapless public. ”

“ When pure and fresh they usually have little or no taste or smell; but, when exposed to the air, they become darker in color, have a disagreeable taste and smell, and are called rancid. As examples of vegetable oils we have cottonseed-oil, linseed-oil, olive-oil, almond-oil and cocoa-butter. Linseed is brought largely from Russia and India; Africa supplies palm-oil; India and the Pacific islands cocoanut-oil; while the best olive-oil is brought from Italy. In animal oils the principal ones are butter, lard, tallow, neatsfoot-oil and sperm-oil. ”

“ The best oil comes from the first crushing, and the pulp is afterwards heated, when a second quality of oil is obtained. Olive trees grow very slowly, and do not fruit for seven years after they are planted. But they live a hundred years, and bear more olives every season. ”

“ Bruise a little the Tuberoses or Jasmine Flowers in a marble mortar with a wooden pestle; put them into a proper vessel, with a sufficient quantity of Oil of Olives, and let them stand in the sun in a close stopped vessel twelve or fifteen days to infuse; at the expiration of which time, squeeze the Oil from the Flowers. Let the Oil stand in the sun to settle, then pour it clear off the dregs. This Oil is very fragrant, and well impregnated with the Essential Oil of these Flowers. ”

“ Mustard-seed oil. The white or yellow seed affords 36 per cent. of oil, and the black seed 18 per cent. The oil concretes when cooled a little below 32° F.
Nut oil, is at first greenish coloured, but becomes pale yellow by time. It congeals at the same low temperature as linseed oil, into a white mass, and has a more drying quality than it.
Oil of olives, is sometimes of a greenish and at others of a pale yellow colour. A few degrees above 32° F. it begins to deposit some white granules of stearine, especially if the oil have been originally expressed with heat. At 22° it deposits 28 per cent. ”

“ The so-called white oil is preferred simply because some markets demand it, but it is undesirable from every point of view. As it is made from over-ripe fruit it soon becomes rancid, and lacks the delicate flavor of oil made at just the proper time. But worse than all this it is made at the expense of the tree, for it is evident that the sooner the tree can be relieved of the burden of its crop, the better it will recuperate for the following season. ”

“ The oil exists chiefly in the outer skins of the seeds, and is easily extracted by boiling water, as in the making a linseed poultice. These seeds contain gum, acetic acid, acetate and muriate of potash, and other salts, with twenty-two parts per cent. of the oil. They were taken as food by the ancient Greeks and Romans, whilst Hippocrates knew the demulcent properties of linseed. An infusion of the seeds has long been given as Linseed tea for soothing a sore chest or throat in severe catarrh, or pulmonary complaints; also the crushed seed is used for making poultices. ”

“ Secondly, it must be observed, that the Essential Oils of plants are, as it were, the chief residence and reservoir of their odorous principle; that they are to be found wherever that principle exists, and never where it is not: so that what we said concerning the Spiritus Rector of plants is applicable here. It must be remembered, that all the parts of some vegetables are odoriferous. Such plants may be put into the alembic all together, and the Essential Oil distilled from all their parts at once. ”

“ As every bale of cotton yields half a ton of seed, and every ton of seed may be made to yield twenty-eight to thirty-two pounds of crude oil, the available quantity is very great. At present only a small quantity is made, the surplus seed being used as manure. Its fertilizing value would not be diminished by removing the oil, which is only a hydro-carbon, i. e., material supplied by air and water. All the fertilizing constituents of the seed are left behind in the oil-cake from which the oil has been pressed. ”

“ We obtained from yellowish seeds 56 per cent. of oil; on a large scale, the yield varies with the variety of seed employed and the process of pressing, from 45 to 50 per cent.
Description—The best kinds of sesamé oil have a mild agreeable taste, a light yellowish colour, and scarcely any odour; but in these respects the oil is liable to vary with the circumstances already mentioned. The white seeds produced in Sind are reputed to yield the finest oil. ”

“ We have every reason to believe that the oils which are found in plants are produced there as the results of certain processes which are proceeding within the plant, and there is no evidence to show that any part of it is ever absorbed in the state of oil by the roots when they are presented to them. ”

“ When used fresh it is weak, and has an unpleasant taste; but after standing a few hours the essential oil unites with the water which is used, and it then becomes considerably stronger, and the flavour is improved. It is prepared by drying the seeds on a kiln and grinding them to a powder. ”

“ The oil obtained from this seed is inferior to good olive oil, but is better adapted for the manufacture of soap.
This plant is not unlike hemp, but the stalk is cleaner and semi-transparent. The flower also is so gaudy, that a field in blossom looks like a bed of florist's flowers, and its aromatic fragrance does not aid to dispel such delusion. It flourishes most upon land which is light and fertile. The fragrance of the oil is perceptibly weaker when obtained from seed produced on wet, tenacious soils. A gallon of seed seems to be the usual quantity sown upon an acre. ”

“ The gathering of the olive crop, too, is a very easy and cheap work. The berries that have fallen to the ground are first picked, then the tree is shaken and the branches struck with long poles to cause the fall of the remaining fruit. The few of them that may be found a little moulded, by a too long contact with the earth, though good enough to make good oil, are generally set apart to be used only with the last pressures, when the lower grade of oil is made. ”

“ Most of the oil of the world is at present extractd by the oil trust, which, in order to secure a slightly increased output, subjects the seed under pressure to a high heat, with the result that in addition to the oil there is pressed out of the mash a variety of resins and essential oils, whose ultimate chemical effect on our colors we cannot as yet determine. ”

“ It is superior in drying powers, tenacity, and body to any other fixed oil. The best oil comes from the Black Sea and the Baltic; that from the East Indian seed is inferior, as the seed is less carefully cleaned, and contains too much stearine. Raw linseed oil is clear and light in color, works smoothly, and is used for internal works, for delicate tints, and for grinding up colors. Boiled oil is much thicker, darker, and more apt to clog. It is used for outside work, as its greater body and rapidity in drying make it a quicker and more efficient protection. ”

“ On the other hand, the oils are extremely inert substances, and undergo chemical changes very slowly; so that there is no likelihood of their being converted into carbonic acid, or any other substance which may be useful to the plant; and as they contain no nitrogen, and consist only of carbon, hydrogen, and oxygen, they can yield only those elements of which the plant can easily obtain an unlimited supply. I can conceive cases in which the oil might possibly produce some mechanical effect on the soil, but none in which it could act as a manure, in the proper sense of the term. ”

“ Linseed oil, as it is pressed from the seed, comes from the cells, carrying with it a certain small definite percentage of water, and it is quite certain that even the best linseed oil that goes into use is not theoretically dry. ”

“ The part of the plant which contains the oil is the fruit. The seeds of most plants contain oil in addition to starch and other principles. Many seeds are used for obtaining oil for various purposes in the arts, as the poppy, rape, mustard, hemp, and flax seeds. In Case 20 is a collection of nuts and seeds containing oil commonly eaten as food. Case 21 contains the analysis of the coco-nut ”

“ Uses.—The green parts, either fresh, dried or in decoction, are used very extensively for flavoring soups, gravies, stews, sauces, forcemeats, sausages, dressings, etc. For drying, the tender stems are gathered after the dew is off and exposed to warm air in the shade. When crisp they are rubbed, the trash removed and the powder placed in stoppered bottles or tins. All parts of the plant are fragrant because of the volatile oil, which is commercially distilled mainly in France. About one per cent of the green parts is oil, which after distillation is at first a reddish-brown fluid. ”

“ It would be impossible to enumerate all the available sources of vegetable oils, for all seeds and nuts contain more or less fatty matter and as we become more economical we shall utilize of what we now throw away. The germ of the corn kernel, once discarded in the manufacture of starch, now yields a popular table oil. From tomato seeds, one of the waste products of the canning factory, can be extracted 22 per cent. of an edible oil. Oats contain 7 per cent. of oil. From rape seed the Japanese get 20,000 tons of oil a year. ”

“ Oil-seeds.—Oil-seeds also form an important crop in all parts of the country, being perhaps more universally grown than any other, as oil is necessary, according to native custom, for application to the person, for food, and for burning in lamps. In recent years the cultivation of oil-seeds has received an extraordinary stimulus owing to the demand for export to Europe, especially to France; but as they can be grown after rice, &c., as a second crop, this increase has hardly at all tended to diminish the production of food grains. ”