Oils of fermented liquors

The substances usually fermented contain a small quantity of e ential oils, which become volatile along with the alcoholic vapours in distillation, and progre ively increase as the spirits become weaker towards the end of the proce . The vapours then condense into a milky liquor. These oils adhere strongly to the alcohol, and give it a peculiar acrid taste. They differ according to the vinous wash from which they are obtained, and combine with greater or le facility with caustic alkalis. 1. Oil of grain spirits. At the ordinary temperature it is partially a white solid; when cooled lower it a umes the aspect of suet, and therefore consists chiefly of stear e ence. Its taste and smell are most offensive; it swims upon the surface of water, and even of spirit containing 30 per cent. of alcohol. It sometimes derives a green colour from the copper worm of the still. When heated it fuses and turns yellow. When it has become resinous by the agency of the atmosphere, it gives a greasy stain to paper. It di olves in 6 parts of anhydrous alcohol, and in 2 of ether; and is said to crystallize when the spirit solution has been saturated with it hot, and is allowed to cool. By exposure to a freezing mixture, the whiskey which contains it lets it fall. Caustic potash di olves it very slowly, and forms a soap soluble in 60 parts of water. It is absorbed by wood charcoal, and still better by bone black; whereby it may be completely abstracted from bad whiskey. According to Buchner, another oil may also be obtained from the residuum of the second distillation of whiskey, if saturated with sea salt, and again distilled. Thus we obtain a pale yellow fluid oil, which does not concrete with cold, po e ed of a disagreeable smell and acrid taste. Its specific gravity is 0·835. It is soluble in alcohol and ether. 2. The oil from potato spirits , has properties quite different from the preceding. It is obtained in considerable quantity by continuing the distillation after most of the alcohol has come over, and it appears in the form of a yellowish oil, mixed with water and spirits. After being agitated first with water, then with a strong solution of muriate of lime, and distilled afresh, it po e es the following properties: it is colourle , limpid, has a peculiar smell, and a bitter hot taste of considerable permanence. It leaves no greasy stain upon paper, remains liquid at 0° F., but cooled below that point it crystallizes like oil of anise-seed. When pure it boils at 257° F.; but at a lower degree, if it contains alcohol. Its specific gravity is 0·821, or 0·823 when it contains a little water. It burns with a clear flame without smoke, but it easily goes out, if not burned with a wick. It di olves in small quantity in water, to which it imparts its taste and the properties of forming a lather by agitation. It di olves in all proportions in alcohol. Chlorine renders it green. Concentrated sulphuric acid converts it into a crimson solution, from which it is precipitated yellow by water. It di olves in all proportions in acetic acid. Concentrated caustic lyes di olve it, but give it up to water. It does not appear to be poisonous, like the oil of corn spirits; because, when given by spoonfuls to dogs, it produced no other effect but vomiting. 3. The oil of brandy or grape spirits , is obtained during the distillation of the fermented residuum of expre ed grapes; being produced immediately after the spirituous liquor has pa ed over. It is very fluid, limpid, of a penetrating odour, and an acrid disagreeable taste. It grows soon yellow in the air. When this oil is distilled, the first portions of it pa unchanged, but afterwards it is decomposed and becomes empyreumatic. It di olves in 1000 parts of water, and communicates to it its peculiar taste and smell. One drop of it is capable of giving a disagreeable flavour to ten old English gallons of spirits. It combines with the caustic alkalis, and di olves sulphur. Oil of Juniper , is obtained by distilling juniper berries along with water. These should be bruised, because their oil is contained in small sacs or reservoirs, which must be laid open before the oil can escape. It is limpid and colourle , or sometimes of a faint greenish yellow colour. Its specific gravity is 0·911. It has the smell and taste of the juniper. Water, or even alcohol, di olves very little of it. Gin contains a very minute quantity of this oil. Like oil of turpentine, it imparts to the urine of persons who swallow it, the smell of violets. Oil of juniper is frequently sophisticated with oil of turpentine introduced into the still with the berries; a fraud easily detected by the diminished density of the mixture. The oil of lavender , is extracted from the flowering spike of the lavandula spica . It is yellow, very fluid, has a strong odour of the lavender, and a burning taste. The specific gravity of the oil found in commerce is 0·898 at the temperature of 72° F., and of 0·877 when it has been rectified. It is soluble in all proportions in alcohol of 0·830, but alcohol of 0·887 di olves only 42 per cent. of its weight. The fresh oil detonates slightly when mixed with iodine, with the production of a yellow cloud. There occurs in commerce a kind of oil of lavender known under the name of oil of aspic or oil of spike , extracted by distillation from a wild variety of the lavandula spica , which has large leaves, and is therefore called latifolia . This oil is manufactured in the south of Europe. Its odour is le characteristic than that of the lavender, resembling somewhat that of oil of turpentine, with which it is indeed often adulterated. It is also so cheap as to be sometimes used instead of the latter oil. Oil of lavender deposits, when partially exposed to the air, a concrete oil, which resembles camphor, to the amount of one fourth of its weight. Oil of lemons , is extracted by pre ure from the yellow peel of the fruit of the lemon, or citrus medic a . In this state it is a yellowish fluid, having a specific gravity of 0·8517; but when distilled along with water till three fifths of the oil have come over, it is obtained in a colourle state, and of a specific gravity of 0·847 at 72° F. This oil does not become concrete till cooled to 4° below 0° F. The oil of lemons has a very agreeable smell of the fruit, which is injured by distillation. It is soluble in all proportions in anhydrous alcohol, but only 14 parts di olve in 100 of spirits of wine of specific gravity 0·837. This oil, especially when distilled, forms with muriatic acid similar camphorated compounds with oil of turpentine, absorbing no le than 280 volumes of the acid gas. Oil of lemons kept long, in ill-corked bottles, generates a quantity of stear e ence, which when di olved in alcohol, precipitated by water, and evaporated, affords brilliant, colourle , transparent needles. Some acetic acid is also generated in the old oil. According to Brandes, the specific gravity of oil of lemons is 0·8786. The oil of mace , lets fall, after a certain time, a concrete oil under the form of a crystalline crust, called by John myristicine . The oil of nutmegs , is extracted chiefly from mace, which is the inner epidermis of these nuts. It is colourle , or yellowish, a little viscid with a strong aromatic odour of nutmegs, an acrid taste, and a specific gravity of 0·948. It consists of two oils, which may be easily separated from each other by agitation with water; for one of them, which is more volatile and aromatic comes to the surface, while the other, which is denser, white, and of a buttery consistence, falls to the bottom. The latter liquefies by the heat of the hand. The oil of orange flowers , called neroli , is extracted from the fresh flowers of the citrus aurantium . When recently prepared it is yellow; but when exposed for two hours to the rays of the sun, or for a longer time to diffuse daylight, it becomes of a yellowish-red. It is very fluid, lighter than water, and has a most agreeable smell. The aqueous solution known under the name of orange-flower water, is used as a perfume. It is obtained either by di olving the oil in water, or by distilling with water the leaves either fresh or salted; the first being the stronger, but the last being the more fragrant preparation. Orange-flower water obtained by distillation, contains besides the oil, a principle which comes over with it, of a nature hitherto unknown; it po e es the property of imparting to water the faculty of becoming red with a few drops of sulphuric acid. The water formed from the oil alone, is destitute of this property. The intensity of the rose-colour is a test in some measure of the richne of the water in oil. The oil of parsley , is extracted from the apium pet rose linum . It is of a pale yellow colour, having the smell of the plant, and consists of two oils separable by agitation in water. Its liquid part floats upon the surface in a very fluid form; its stear e ence, which falls to the bottom, is butyraceous and crystallizes at a low temperature. This concrete oil melts at 86° F. The oil of pepper , is extracted from the piper nigrum . In the recent state it is limpid and colourle , but by keeping it becomes yellow. It swims upon the surface of water. In odour it resembles pepper, but is devoid of its hot taste.