At the present time the growing and distillation of volatile oil-producing plants are practiced to a limited extent in several parts of the country. The most conspicuous example is peppermint, which is grown in southern and central Michigan, northern Indiana and in Wayne county, New York. Michigan is at present probably the most important pepper mint oil region of the world. Japan produces a large quantity of an oil called commercially pepper mint oil. England and Germany are smaller pro ducers. Wormwood oil, formerly grown chiefly in France and other parts of Europe, is now grown largely in Michigan, Wisconsin and Nebraska, the United States furnishing a very considerable part of the world's product. Spearmint oil is also pro duced in small quantity. Spearmint supplies mate rial for mint julep.
Among the volatile oils produced in the United States, some are obtained from wild plants which are collected in the fields and forests for distilla tion. Sassafras oil is distilled at scattered points in Pennsylvania, Virginia and other parts of the country occupied by the sassafras tree, even as far west as Missouri. Wintergreen oil is distilled in small quantities in Michigan, Connecticut and other regions where the wintergreen plant and the sweet birch (which yields the oil on distillation of the bark) are found abundantly. Perhaps the most im portant single volatile oil is distilled from the resinous substances which exude from the wounded trunks of the turpentine-yielding pines. The resi nous exudate on distillation yields the oil of tur pentine of commerce. On the Pacific coast there is a sparing distillation of the leaves of the eucalyptus trees grown so frequently in that region. The ker nels of California bitter almonds, and to a much larger extent the kernels of apricots, are also a commercial source of the so-called oil of bitter almonds.
Volatile oil importation.
In addition to the above home production, this country imports volatile oils and products derived from them to no small extent. In the following tables, the report of the National Customs author ities for the year ended June 30, 1905, gives the sorts, values, and quantities of some of the most important kinds of products imported during the period indicated: it to a low temperature, occurs in many prepara tions because of its antiseptic properties, and in the form of cones or pencils for use externally in headaches, neuralgia and the like. Eucalyptol, ob
tained from eucalyptus oil, and thymol, obtained chiefly from the oil of thyme, are likewise highly valued antiseptics and enter into many washes, sprays and other medicinal preparations. Some oils of the class here concerned are employed almost solely for medicinal purposes, such as oil of Ameri can wormseed. Others have a limited use in various ways in the arts and sciences, e. g., oil of red cedar wood and of white cedar in microscopic work.
Anise. [See Medicinal, Condimental and Aromatic Plants, page 458.] Bitter Almonds (Prunus Amygdalus, var. amara, DC.). Rosaccee.
The so-called oil of bitter almonds is obtained from the kernel of bitter almonds, apricots and peaches. The kernels are coarsely ground, submit ted to great hydraulic pressure to remove the fatty oils present, and the remaining cake after finer grinding is macerated in several times its volume of water and left for twelve hours. The volatile oil does not exist ready formed in the seed, but is Uses of volatile oils.
Volatile oils meet with a wide use in the making of perfumery, for which their pleasing odor and high degree of volatility render them especially valuable. They are used not only mixed in propor tions designed to produce a given fragrance in the form of solutions seen in the usual commercial perfumeries, but they find their way into many other preparations in which pleasing odor is desired. Soaps alone make a striking illustration. As flavor ing agents they play an important part in domestic economy. The "essences" of the kitchen, bakery and confectionary factory are in large part prepa rations of such volatile oils as give the desired flavors to cakes, ice creams and candies. They are also used in various beverages, liquors and cordials. The French beverage, absinthe, is distinguished by the presence in it of oil of wormwood. These oils and their products are also used in the manu facture of remedies. Menthol, a crystalline sub stance obtained from peppermint oil by subjecting developed by the chemical action of bodies present in the kernel. Amygdalin, a glucoside present, when acted on by emulsin, a splitting ferment also present in the kernel, splits up, in the presence of water, into grape-sugar, prussic acid and benzalde hyde. After a sufficient time has elapsed for the oil to form, distillation occurs. California is the chief American source of this very volatile and poisonous oil.