A plantation with five labourers contains on an average 70,000 to 80,000 shrubs, and yields 40 to 50 catties (1 catty = 1⅓ lb. = 604·8 grammes) of gambier daily.
Description—Gambier is an earthy-looking substance of light brown hue, consisting of cubes about an inch each side, more or less agglutinated, or it is in the form of entirely compact masses. The cubes are externally of a reddish-brown and compact, internally of a pale cinnamon hue, dry, porous, friable, devoid of odour, but with a bitterish astringent taste, becoming subsequently sweetish. Under the microscope, the cubes of gambier are seen to consist of very small acicular crystals.
Chemical Composition—In a chemical point of view, gambier agrees with cutch, especially with the pale variety made in Northern India ([p. 242]). Both substances consist mainly of Catechin,[1284] which may be obtained in the hydrated state as slender colourless needles, by exhausting gambier with cold water, and crystallizing the residue from 3 or 4 parts of hot water, which on cooling deposits nearly all the catechin. Ferric chloride strikes with the solution of catechin, even when much diluted, a green tint. If it is shaken with ferrous sulphate and an extremely small quantity of bicarbonate of sodium, a violet colour makes its appearance. The same reactions are produced by various substances of the tannic class.
The yellowish colouring matter of gambier was determined by Hlasiwetz (1867) and Löwe (1873) to be Quercetin, which is also a constituent of cutch. Quercetin is but very sparingly soluble in water, yet it is nevertheless found, in small quantity, in the aqueous extract of cutch, from which it may be removed by means of ether. As many species of Nauclea contain, according to De Vry,[1285] Quinovic Acid, it is probable that that substance may be detected in gambier.
Some fine gambier in regular cubes which we incinerated left 2·6 per cent. of ash, consisting mainly of carbonates of calcium and magnesium.
Commerce—Singapore, which is the great emporium for gambier, exported in 1871 no less than 34,248 tons, of which quantity 19,550 tons had been imported into the colony chiefly from Rhio and the Malayan Peninsula.[1286] In 1876 the export had increased to more than 50,000 tons of pressed block gambier and 2,700 tons of cubes. In 1877 it diminished to 39,117 tons, owing to difficulties which had arisen between the Chinese dealers, who supplied the drug in a rather wet state, and the European exporters. Of the above quantity 21,607 tons were shipped for London, 7,572 for Liverpool, 2,345 for Marseilles. Gambier usually fetches a lower price[1287] in the London market than cutch.
The quantity imported into the United Kingdom in 1872 was 21,155 tons, value £451,737, almost the whole being from the Straits Settlements.
Uses—Gambier, under the name of Catechu, is used medicinally as an astringent, but the quantity thus consumed is as nothing in comparison with that employed for tanning and dyeing.
CORTEX CINCHONÆ.
Cortex Peruvianus, Cortex Chinæ; Cinchona Bark, Peruvian Bark; F. Ecorce de Quinquina; G. Chinarinde.