TANS AND DYES 229 



GAMBIER 



Gambier is used both as a dye and a tanning agent. It is 

 also frequently called cutch, terra japonica, and catechu, 

 although these terms are not strictly synonymous. The prod- 

 uct which comes upon the market under the name gambier is 

 derived from Uncaria gambir, a climbing shrub of the madder 

 family, largely cultivated near Singapore and in Java and also 

 from Acacia catechu, and A. surtna. In preparing the tanning 

 material the leaves and twigs of U. gambir and the heartwood 

 of A. catechu are boiled until they yield a sirupy extract, which 

 is then allowed to harden. Gambier comes upon the market 

 in purple resin-like masses. It contains 25 to 50 per cent, of 

 tannic acid. The catechu obtained from A. catechu is chewed 

 by the natives of India as a gum. This plant should not be 

 confused with Areca catechu or the Betel-nut palm. Gambier 

 is also used to some extent in medicine, but chiefly as a dye- 

 stuff for the production of browns, fawns, olives, and drabs. 

 It gives a strictly fast color and is much used in dyeing khaki. 

 The United States imports nearly 14,000,000 pounds annually. 

 The leaves and spherical flower clusters of the gambier re- 

 semble somewhat those of the button bush of the United States. 

 This plant is now extensively cultivated in Java, where much 

 profit has been found in its production with the result that the 

 area cultivated to gambier is increasing. 



MANGROVE 



Mangrove trees of several species, particularly Rhizophora 

 mucronata, R. mangle, etc., are native of Ceylon and the Orien- 

 tal Tropics. These trees are of medium size and exhibit a 

 wide-spreading growth of branches. They are found in the 

 brackish swamps and muddy lagoons, inside coral reefs, and in 

 similar situations. The mangrove tree appears to stand on a 

 much branched system of roots, somewhat resembling Pan- 



