Page:The American Cyclopædia (1879) Volume VI.djvu/149

DISTILLATION When large products are required, more effi- cient forms of apparatus must be employed. Such are stills, in which the retort as well as the condensing portion is made of met- al, generally copper or iron. Usually, instead of a receiver of the ordinary form, the neck of the retort, or a tube from the boiler, is converted into a long coil, called a worm, which, being immersed in a tub of water, causes condensation of the vapors within. A simple form of still, often used when consider- able quantities of distilled water are required, and also for other pharmaceutical purposes, is represented in fig. 2. The retort is all that portion of the apparatus which sets in and upon the furnace, including the neck c, ter- minating at d, in the worm 5, d, which passes through a cooler e, which is supplied with cold water by the funnel &, the water entering at the bottom and flowing out at the top. It will be seen that the form of this apparatus will prevent some of the less volatile portions of FIG. 2. Still. the liquid subjected to distillation from passing over, as they may with the application of much heat in the common retort in fig. 1, a considerable condensation taking place in the dome 5. Liebig's laboratory distilling appara- tus is constructed by passing the neck of a re- tort into a Liebig's condenser, which consists of a glass tube surrounded by a metallic one, of tin or copper, in the lower part of which water enters, flowing out at the top. The ar- rangement is on the same plan as the still in fig. 2, only instead of a worm there is a straight tube. The preparation of an alcoholic liquor by separating the more volatile portions of the fermented juices of fruits and infusions of grains does not appear to have been understood by the ancients. Ure says : "It seems to have been invented by the barbarians of the north of Europe as a solace to their cold and humid clime, and was first made known to the south- ern nations in the writings of Arnoldus de Villa Nova, and his pupil, Raymond Lully of Majorca." But there are now few nations above the condition of savages who do not prepare some kind of alcoholic liquors by dis- tillation. The fermented juices of the grape and other fruits, and the fermented infusion of grape sugar derived from malted liquors, contain the same intoxicating principle, alco- hol, which it is the object of distillation to ob- tain in a more condensed form, and which when so obtained from liquids of different qualities retains the peculiar aroma and flavor of the plant, until by repeated distillations and rectifications the pure alcohol is at last ob- tained from peculiar volatile oils or flavors. All the juices of plants which can undergo vinous fermentation, and all vegetable matters which contain starch, may thus be made to produce alcoholic liquors. Some animal fluids also, which contain saccharine matters, as milk, may be made to furnish alcohol by fer- mentation and distillation. An intoxicating liquor from this source, called Jcumiss, is made in Tartary, both simply fermented and dis- tilled. The fruits of each country furnish spirits of their peculiar flavors when these are obtained directly from the fermented juice ; but if this is first allowed to crystallize, the sugar so obtained, on being redissolved and fermented, is found to have lost the aroma of the plant. Thus, the high flavor of the rum which is distilled from fermented fresh cane juice is not found in the distillate from fer- mented sugar and molasses. Sugar-growing countries produce rum, vine-growing countries brandy, and grain-growing countries whiskey and gin. The Chinese manufacture a distilled liquor from rice, and the inhabitants of Kam- tchatka another from mushrooms. The pro- cesses of obtaining these liquors are essentially the same, except that the cereals require some preparatory operations before they are ready, like the saccharine juices, for fermentation, and these operations are almost identical with those employed in brewing ale ; the only dif- ference being that in preparing the wort which after fermentation is to be distilled, the action of the diastase in the malt is continued until the dextrine is transformed into grape sugar. The grain is subjected to the process of mashing, and the resulting wort to that of cooling and fermentation, after which follows the distillation. A brief account of the man- ufacture of whiskey, as performed in the great distilleries of Scotland, will sufficiently explain the various operations. Barley is commonly used as the starchy material, and is more 01' less mixed with oats, rye, or other grains. It may be malted wholly or in part, or may be used with sugar. Barley malt is the best ma- terial, but the heavy duty imposed upon it restricts its use. According to Dr. Thomson, 40 bushels of ground barley are mixed with 20 bushels of bruised malt, in a mash tun of cast iron, together with about 750 gallons of water,