338 RUBIACE^. 



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 gambler was determined by 

 Hlasiwetz (1867) and Lowe (1873) to be Quercetin, which is also a con- 

 stituent of cutch. Quercetin is but ver}"- 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 JSfauclea contain, according to De Vry,^ Quinovic Acid, it 

 is probable that that substance may be detected in gambler. 



Some fine gambler 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 gambler, 

 exported in 1871 no less than 34,248 tons, of which quantity 19,550 

 tons had been imported into the colony chiefly from E,hio and the 

 Malayan Peninsula.^ In 1876 the export had increased to more than 

 50,000 tons of pressed block gambler 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. 

 Gambler usually fetches a lower price* 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 — Gambler, under the name of Catechu, is used medicinally 

 as an astringent, but the quantity thus consumed is as nothing in com- 

 parison with that employed for tanning and dyeing. 



CORTEX CINCHONA. 



Cortex Peruvianus, Cortex CJmice ; Cinchona Bark, Peruvian Bark ; 

 F. Ecorce de Quinquina ; G. Chinarinde. 



Botanical Origin — The genus Cinchona constitutes together with 

 Ca^carilla (including Buena and Cosmibuena), MeTnijia, Ladenbergia, 

 Macrocnemum, and about 30 other nearly allied genera, the well- 

 characterized tribe Cinchonece of the order MubiacecB. This tribe 

 consists of shrubs or trees with opposite leaves, 2-celled ovary, capsular 

 fruit, and numerous minute, vertical or ascending, peltate, winged, albu- 

 minous seeds. 



(A.) Remwbrks on the genus. — The genus Cinchona is distinguished 

 by deciduous stipules, flowers in terminal panicles, 5-toothed superior 

 calyx, tubular corolla expanding into 5 lobes fringed at the margin. 

 The corolla is of an agreeable weak odour, and of a rosy or purplish hue 

 or white. 



1 PAarro. /0Mr». vi. (1865) 18. 3 17^. per cwt., March 1879; see 



■^ Blue Book of the Colony of the Straits Catechu, page 242, note 3. 

 Settlements for 1871. 



