The root of Alkanna tinctoria, Tausch; (Anchusa tinctoria, Linné; Lithospermum tinctoria).
COMMON NAMES: Alkanet, Dyer's bugloss.
ILLUSTRATION: Artus' Hand Atlas, Vol. II., p. 438.
Botanical Source.—This plant is a weak, hairy herb, about a foot high, with alternate, oblong, entire, bicuspid leaves. The flowers are small, and disposed in terminal racemes, usually in pairs, which unroll as the flowers expand. The calyx is 5-lobed, and the corollas funnel-shaped, with a red tube about the length of the calyx-lobes, and a blue, 5-parted limb. The fruit consists of 4 distinct nutlets, which are contracted, and not hollowed, at the base.
History and Chemical Composition.—The Alkanet plant is indigenous to, and cultivated in the southern part of Europe. The roots of the cultivated plants are not so rich in the red coloring matter as are those grown in their native soil. The genus Alkanna is closely related to Anchusa and Lithospermum, and the roots of all three genera yield red coloring matters. Alkanet root contains the red coloring matter—anchusin or alkanet-red. To obtain it (Wittstein) the root is exhausted with water to remove gum and foreign coloring matters, then dried, ground, and percolated with alcohol. The alcoholic tincture is acidulated with hydrochloric acid, distilled, and evaporated to the consistence of a soft extract; this is exhausted with ether, water added, and, after agitation, the lower liquid separated. The ethereal solution is again washed with water, decanted, and evaporated. Anchusin, is dark, red-brown, brittle, neutral, and volatile, subliming in violet-red vapors. It is insoluble in water, soluble in chloroform and alcohol, more soluble in ether and oils. Sulphuric acid dissolves it with an amethyst color; solution of alkalies, with blue. The other constituents of the plant are unimportant.
Description.—Alkanet root, as obtained in this market, is often worm-eaten, and of very inferior quality. It appears as fragments, mixed with entire roots from 6 to 12 inches in length. They are dark purple externally, lighter within, pliable and spongy. The root is largely employed by manufacturers of pomades, hair oils, ointments, etc., for the purpose of coloring them. For these purposes, a solution of the alkanet-red is made by covering the crushed root with castor-oil, macerating, and straining; the deep red coloring matter is thus obtained, in solution, and this solution is added to the oil or pomade until the desired shade is produced.
Uses.—This root is rarely, if ever, employed therapeutically, though stated to possess emollient properties. Its chief use among pharmacists is for coloring certain articles. It is asserted that it is used to color adulterated wines.
Other Coloring Agents.—ARNOTTA, Annotta, Annatto, Orellana, Orleana. These various names refer to the coloring principle of the pulp of the seeds of Bixa Orellana, Linné (Nat. Ord., Bixaceae), a medium-sized tree of the American tropical regions. The whitish, obovate and angular seeds are inclosed in deep-red pulp. According to Peckholt (A. J. P., 1859), the coloring matter is obtained by soaking the bruised seeds in water (or allowing them to ferment in water), rubbing the pulp from the seeds by hand, passing the liquid mass through a sieve, and finally mashing the seeds and washing again with more water. The coloring matter is allowed to settle, then dried, and formed into cakes or cylindrical pieces. A coloring matter also remains in the water employed. Prime annotta is plastic, generally quite soft, having the red color of blood, becoming, when exposed to air, of a deep reddish-brown. When dry or old, it is brittle and hard. It has an unpleasant, saline, bitterish taste, and a peculiar sweetish odor. It is scarcely soluble in water, in which it softens, however, and to which it imparts a yellow color. Alcohol, fixed oils, ether, and alkalies dissolve it, an orange-red or deep-red solution being formed. Heat does not fuse it, and it is inflammable. There are two grades known in commerce—the French (flag annotta), the best for coloring purposes, though it possesses the most disagreeable odor, probably having been prepared by the fermentation process; and the Spanish (Brazilian), which is not unpleasant to the sense of smell. Annotta contains two coloring principles; one, discovered by Preisser, a non-crystalline, bright-red, resinous body, called bixin (C15H18O4, Stein; C28H35O5, Etti); orellin, the second coloring body, is yellow, and soluble in water. Nitric acid colors bixin yellow, producing an odorous body resembling musk in odor; sulphuric acid colors bixin blue. Besides other compounds, annotta contains a terebinthinous body and a fatty acid. The seeds contain phosphoric acid, silica, and potassa (Ebert). Annotta is subject to adulteration, the agents employed being sand, chalk, gypsum, brickdust, red ochre, turmeric, and starchy bodies. The mineral impurities will refuse to dissolve in boiling alcohol. Annatto is employed to dye fabrics, especially silk, an orange-yellow fugitive color being imparted. In pharmacy, ointments and plasters are sometimes colored with it, while in the arts it is used to produce "butter color," for giving yellowness to butter and cheese. This preparation may be obtained by digesting annotta, 1 part, until wholly disintegrated, in alcohol, heating with olive oil (or some other bland oil) 4 or 5 parts, by weight. Another method is to add to olive oil (1 part), extract of arnotta (10 parts). A small quantity of turmeric is added when the preparation is desired as a cheese-color.
Related entry: Caesalpinia
BRAZIL WOOD. Several South American and West Indian species of Caesalpinia yield this red dye-wood. There are two chief commercial kinds, (1) Pernambuco (Fernambuco) wood, the most valued, and the Brazil wood proper, from Caesalpinia Braziliensis and C. crista;and (2) Brasiletto, from the West Indian and Jamaican C. vesicaria, of less value. Analogous to Brasiletto are the sappan, or samfen wood (from C. Sappan), and the Nicaragua, or peach wood (C. echinata). Brazil wood was formerly used in medicine, but now has only a limited use in pharmacy, viz., to color tinctures. It is largely used in dyeing, and to some extent in preparing lakes and red ink. Its coloring matter is extracted by water. The wood has a faintly-sweetish taste, and practically no odor. Brazilin, or brasilin (C16H14O5), the coloring principle, is sulphur-yellow (colorless if absolutely pure) and crystallizable, sparingly dissolved by water, the solution being clear, nearly colorless, and sweet. Acids do not affect the solution, but alkalies redden it. Ether and alcohol produce pale yellow solutions. Brazilin quickly becomes red in the sunlight, and more slowly in diffused light, hence it must be kept in the dark. The red color produced by exposure to light and air is due to the production of brazilein (C16H12O5).
Onosma echioides, Lamarck. South Europe. A hairy, rough perennial, whose flowers, at first white, finally become yellow. The root, which is conical, and has a deep-red bark which is black on the outer surface, is used as a substitute for alkanna in coloring.
Lawsonia alba, Lamarck. (Nat. Ord., Lythraceae). Henna, or Alhenna, is produced from this plant, which is much esteemed by the inhabitants of India and other Oriental lands. Mohammed is said to have spoken of it as the "best of herbs." Innumerable conditions are said to be curable with it, among them headache, smallpox, leprosy, and "burning feet," a peculiar and obscure affection met with occasionally in India, etc. Dioscorides speaks of it as a plant "whose leaves dye the hair of an orange color." In Africa and Asia, and among the Mahometans especially, the custom is in vogue of dyeing the feet and hands orange-yellow, a practice said to have prevailed among the ancient Jews and Egyptians. The coloring matter, which appears like a brown-resinoid material, is a sort of tannin to which the name hennotannic acid was given by Abd-el-Aziz Herraory.