2. (W. Procter.) Vanilla (cut into thin transverse slices), 1 oz.; sugar, 3 oz.; triturate until reduced to fine powder, put it into a strong pint bottle, along with syrup, 1⁄2 pint; water, 2 oz.; tie down the cork, and set the bottle for half an hour in boiling water; cool, strain, and treat the residue in a like manner with a mixture of water, 6 fl. oz., and rectified spirit, 1 fl. oz.; lastly, mix the two products. Greatly inferior to the last.
LIQ′UORICE. Syn. Stick liquorice; Liquoritia,
Glycyrrhizæ radix (B. P.), Glycyrrhizæ radix, Glycyrrhiza (Ph. L. & D.), G. glabra (Ph. E.), L. “The root or underground stem of the Glycyrrhiza glabra, fresh and dried, cultivated in Britain.” “The recent and the dried root of Glycyrrhiza glabra,” or common liquorice. “The fresh root is to be kept buried in dried sand for use.” (Ph. L.) It has a sweetish taste, and is slightly aperient, expectorant, and diuretic. It is a popular demulcent and pectoral. Its extract and solution are much used as a domestic remedy for cough. As a masticatory it allays thirst and irritation.
Composition of the fresh root of liquorice:
| Glycyrrhizin | 8·60 |
| Gum | 26·60 |
| Matter soluble in alcohol, chiefly resin | 0·75 |
| Albumen | 0·97 |
| Starch | 22·91 |
| Woody fibre | 13·36 |
| Moisture | 26·81 |
| Ash, 3·07 per cent. | — |
| ——— | |
| 100·00 | |
| (Hassall.) |
Roussin asserts that the sweetness of liquorice root is not due to glycyrrhizin, as has been hitherto assumed, but to an ammoniacal compound of that substance. Glycyrrhizin, when purified four successive times by dissolving it in alcohol, and precipitating the foreign matter accompanying it by ether, is a yellowish substance, insoluble in cold water, and almost tasteless. Treated with dilute solution of potash or soda, it rapidly develops a sweet taste. In liquorice root, however, it is not contained in combination with either of these two alkalies, but appears to exist as an ammoniacal compound, for solutions of potash and soda liberate ammonia, both from the root and the extract. In its compounds with the alkalies glycyrrhizin plays the part of an acid, as it forms true salts capable of undergoing decomposition with most of the metallic salts, and also with the salts of the organic alkaloids. With ammonia it forms two compounds, a basic salt, which yields a deep yellow solution, and another containing less ammonia, the solution of which has an amber colour. The former is produced by dissolving glycyrrhizin in water with an excess of ammonia. Upon evaporating the resulting deep yellow solution to dryness it leaves a yellowish, scaly, shining, brittle, non-hygroscopic residue, which constitutes the second ammoniacal compound. This is readily soluble in cold water, to which it imparts a pale yellow colour and a very sweet taste. The solution turns deep yellow on the addition of a few drops of solution of ammonia, owing to the formation of the basic compound. The pale yellow solution possesses, in a marked degree, the taste of liquorice root, which, indeed, owes its sweetness to this glycyrrhizate of ammonia, or ammoniacal glycyrrhizin, as
the author prefers to call it. One gram of this compound imparts the sweet taste of the root to two litres of water.
The author gives the following process for the preparation of the ammoniacal glycyrrhizin in the pure state: The carefully-selected roots, freed from all portions presenting a dark fracture, are scraped, and then well pounded, so as to reduce them to a kind of stringy tow. This substance is macerated in cold distilled water for some hours, pressed, and treated a second time in the same manner. The two liquors are mixed and allowed to stand for some time to deposit the starch. The supernatant liquor is then boiled and filtered, to separate the coagulated albumen. After cooling, sulphuric acid diluted with its weight of water is added gradually, with brisk stirring, until a precipitate is no longer formed. The precipitate, at first gelatinous and flocculent, after standing some time, forms a compact semi-solid mass at the bottom of the vessel. The supernatant liquor is rejected, and after roughly washing the precipitate several times with pure water it is finally kneaded repeatedly in distilled water until all trace of acidity has disappeared. The mass is then well drained and agitated in a flask with three times its weight of 90° alcohol until dissolved, when a similar quantity of 96° to 98° alcohol is added to the syrupy liquid so produced. A little pectic acid is thus precipitated, which is removed by filtration. Ether is then added to the alcoholic liquor as long as a precipitate is formed. After standing twenty-four or even forty-eight hours a blackish pitchy substance is deposited, which adheres to the glass, and allows of the clear liquor being decanted. To this clear liquor is added, in small quantities at a time, alcohol of 90° charged with gaseous ammonia, which determines the formation of a yellow, rather heavy, flocculent precipitate of glycyrrhizate of ammonia. This precipitate is washed rapidly on a fine cloth with a mixture of equal parts of alcohol and ether, pressed and dried in a current of warm air, or over sulphuric acid.
The author suggests the addition of ammoniacal glycyrrhizin to pill masses, powders, or mixtures, and states that its power of masking the taste of nauseous medicines is equal to 100 times its weight of sugar. Sulphate of quinine, sulphate of magnesia, iodide of potassium, and ipecacuanha, lose much of their taste by such an addition.
A dose of cod-liver oil or syrup of iodide of iron is rendered more palatable by being preceded by a small dose of the solid ammoniacal glycerin.[21] Its extract is the common LIQUORICE, Spanish liquorice, or Spanish juice, of the shops. See Extract, &c.