Liquorice, Or Lieorice, a medicinal article derived from plants belonging to the genus glycyrrhiza (Gr. yrvkvg, sweet, and pica, a root), commonly from the G. glabra, and probably a portion is furnished by 0. echinata. A species, 0. lepidota, is found on the shores of Lake Erie, but more abundantly further west, which has in a measure the taste of the foreign plant. The glycyrrhizas are herbaceous plants of the natural order leguminosce, having erect stems 4 or 5 ft. high, with few branches, leaves alternate, pinnate; flowers violet or purple, formed like those of the pea, and arranged in axillary spikes on long peduncles. The fruit is a smooth or bristly pod, with one to four small kidney-shaped seeds in a single cell. The root, which is perennial, attains the length of several feet, and is sometimes more than an inch in diameter. When three years old it is dug, and when cleansed and dried is ready for the market, in which state it is known as liquorice root or stick liquorice. The extract of liquorice, sometimes called in commerce Spanish juice, and popularly known as ball liquorice, is prepared by boiling the root with water; the saturated decoction is then decanted off and evaporated to proper consistence for forming the substance into cylinders 5 or 6 in. long and an inch in diameter.
These, packed in cases with bay leaves, are the extract of liquorice of commerce. It is dry and brittle, of shining fracture, of sweet and peculiar taste, and, if pure and genuine, entirely soluble in water. This, however, is rarely the case, for the article is subject to gross adulterations. The Spanish liquorice is frequently nothing else than a mixture of the juice with the worst kind of gum arabic, called Barbary gum. Metallic copper scraped off the evaporating pans is very frequently present; and starch and flour sometimes constitute nearly one half of the substance. These adulterations Dr. Hassall found extended to the different kinds of roll and pipe liquorice, and Pontefract lozenges, which last, made near the town of that name, are usually considered as presenting a very pure form of the extract. Liquorice is refined by dissolving the impure extract in water without boiling, separating the insoluble matters and also the acrid oleo-resinous portions which by long boiling were extracted from the root, and reforming the article in cylinders of the size of pipe stems.
But in the place of the substances removed others are commonly introduced, as sugar, flour, starch, and gelatine. - The most important proximate principles found in liquorice are: 1, glycyrrhizine or glycione, a glucosite (C48H36O18, or C16H12O6), a transparent yellow substance, of a sweet taste, but distinct from sugar, scarcely soluble in cold but exceedingly so in boiling water, with which it gelatinizes on cooling; 2, a crystallizable principle identical with asparagine; 3, a brown acrid resin. Besides these, it contains starch, albumen, extract of gum, salts, etc. Glycyrrhizine is present, according to Dr. Hassall, in the fresh root, the undecorticated powder, and the decorticated powder, in the respec-five percentages of 8.60, 10.40, and 13.0, and the pure extract should contain 10 to 15 per cent. The commercial extracts vary more or less from this. Liquorice is used in medicine chiefly as a demulcent, especially in affections of the bronchial tubes, and also to cover the taste of acrid or disagreeable substances, as seneca or hydrochlorate of ammonia. It is possible that the resin may have some therapeutic action in chronic bronchial affections. The decoction of the root, a solution of the extract, or the extract in substance, may be employed.
The powder may be used to impart bulk and consistence to other drugs in making pills or lozenges.
Liquorice Plant (Glycyrrhiza glabra).