334 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



to India and Burmah, and from the leaves and twigs of Uncaria 

 (Ourouparia) Gambir (Fam. Rubicaceae), a climbing shrub or liane 

 indigenous to Malacca, Java and Sumatra and mostly cultivated 

 near Singapore, the former being known as " black catcheu " or 

 " cutch," and the latter as " pale catechu," " gambir," or " terra 

 japonica." These extracts are prepared by boiling the parts of the 

 trees and shrubs yielding catechu with water, evaporating the strained 

 liquid to a syrupy consistence and allowing it to harden. 



Black Catechu. In irregular masses, with fragments of leaves or 

 mats upon the outside reddish-black, somewhat shiny; brittle, more 

 or less porous internally; odor slight; taste astringent and sweetish. 



Inner Structure. Pegu Catechu, when examined in water, shows 

 in the residue a number of anisotropic octahedral crystals (Fig. 36), 

 from 0.010 to 0.035 mm. in diameter; a few tracheae associated with 

 wood fibers and leaf fragments; numerous reddish brown granular 

 or amorphous fragments containing more or less rod-shaped 

 bacteria. 



Catechu is somewhat soluble in cold water, and almost entirely 

 soluble in boiling water, the solution giving an acid reaction, a 

 dense precipitate with solutions of copper sulphate and a greenish- 

 black precipitate with dilute ferric chloride solution; not less than 

 70 per cent should be soluble in 90 per cent alcohol. Few or no 

 starch grains or vegetable tissues should be present, and the ash 

 should not be more than 5 per cent. 



Gambir or Pale Catechu. Usually in more or less porous irreg- 

 ular cubes, about 25 mm. in diameter; externally dull reddish- 

 brown; friable; internally paler, consisting chiefly of microscopic 

 crystals when examined in hydrated chloral; odor slight; taste bitter 

 and very astringent. About 85 per cent of gambir is soluble in 

 water and about 70 per cent is soluble in 90 per cent alcohol. The 

 aqueous solution gives an intense green color with dilute ferric chloride 

 solution and does not yield a precipitate with copper sulphate solution. 



Inner Structure. Upon scraping a piece of gambir and mounting 

 the separated fragments in solutions of hydrated chloral it shows 

 numerous acicular crystals from 0.010 to 0.030 mm. which separate 

 (Fig. 36) close to the edges of the fragments, and gradually dissolve, 

 leaving a few of the non-glandular hairs, which, when entire, may 

 be as long as 0.350 mm., the walls being very thick and with an even 

 outline; a few fragments of leaves showing small narrow tracheae 

 with spiral or annular markings; a few starch grains single or com- 

 pound, from 0.005 to 0.015 mm. in diameter, a number of bacteria 

 are usually present. 



