LIQUORICE. The hard and semi-vitreous sticks of paste, black in colour and possessed of a sweet somewhat astringent taste, known as liquorice paste or black sugar, are the inspissated juice of the roots of a leguminous plant, Glycyrrhiza glabra, the radix glycyrrltizx of the pharmacopoeia. The plant is cultivated throughout the warmer parts of Europe, especially on the Mediterranean shores, and its geographical limits travel eastward throughout Central Asia to China, where its cultivation is also prosecuted. In the United Kingdom it is grown in Surrey and in Yorkshire. The roots for use are obtained in lengths of 3 or 4 feet, and varying in diameter from :I to 1 inch, soft, flexible, and fibrous, and internally of a bright yellow colour with a characteristic sweet pleasant taste. To this sweet taste of its root the plant owes its generic name Glycyrrhiza (the sweet root), of which liquorice is a corruption. According to time analysis of Sestini (Gas. China. Ital., vol. viii. p. 131), time root dried at 110° C. has the following composition :resin, fat, and colouring matters, 3.220; glycyrrhizin, 6.378; starch, 57.720 ; cellulose, 19.790 ; albuminoid substances, 6.373; ammonia (combined), 0'043; asparagine, 2.416; ash, 4.060. It is to the sugar-like body glycyrrhizin in combination with ammonia that the peculiar taste and properties of liquorice root are due. Glycyrrhizin in itself is a tasteless nearly insoluble substance having the composition of C„II,p6 ; but in combination with ammonia, potash, or soda it develops its sweet taste. It is easily precipitated from its combination by the influence of mineral acids. Liquorice has been known and its virtues appreciated from the most remote periods, and the root is an article of some commercial importance on the Continent.
Stick liquorice is made by crushing and grinding the roots to a pulp, which is boiled in water over an open fire, and the decoction separated from the solid residue of the root is evaporated in copper pans till a sufficient degree of concentration is attained, after which, on cooling, it is rolled into the form of sticks or other shapes for the market. The preparation of the juice is a widely extended industry along the Mediterranean coasts ; but the quality best appreciated in the United Kingdom is made in Calabria, and sold under the names of Solazzi and Corigliano juice. The liquorice grown in Yorkshire is made into a confection called Pontefract cakes. Liquorice in various forms is a popular remedy for coughs ; and it is largely used by children as a sweetmeat. It enters into the composition of many cough lozenges and other demulcent preparations ; and in the form of aromatic syrups and elixirs it has a remarkable effect in masking the taste of nauseous medicines, a property peculiar to glycyrrhizin. A considerable quantity of liquorice is used in the preparation of tobacco for chewing. Commercial liquorice paste is frequently much adulterated, and often contains distinct traces of copper, apparently derived from the vessels in which the juice is inspissated.