440 DRIED JUICES 



carbuncles, is obtained by making an incision and inserting a trough- 

 shaped piece of tin by which the treacly liquid as it drains from the 

 cut is carried into buckets or tins. In a few days it dries into a solid 

 mass which soon becomes friable, breaking up into very dark frag- 

 ments ; or it may be evaporated by boiling, and the official drug is 

 probably prepared by this method. The yield of each tree is very 

 variable, the average being about a litre, some yielding none, others 

 as much as 18 litres (Maiden, 1897). 



Description. Red gum is seen in commerce in small pieces, about 

 the size of a pea or less. They are of a dark reddish brown colour, 

 opaque, and more or less dusty, but thin laminae are transparent and 

 ruby-red, the powder being pale reddish in colour. It is somewhat 

 tough, and has when chewed an astringent taste, colouring the saliva 

 red and adhering to the teeth. Cold water should dissolve from 80 to 

 90 per cent. According to Brownseombe (1899) good qualities should 

 yield not less than the latter percentage. 



The student should observe 



(a) The reddish colour, 



(b) The dusty appearance 



of the drug. 



Constituents. Red gum contains about 47 per cent, of kinotannic 

 acid (Maiden, 1897), which is undoubtedly its principal constituent. 

 There is also present kino-red, a gelatinisable tannin glucoside, cate- 

 chin, pyrocatechin, and about 15 per cent, of moisture, the remainder 

 consisting of substances not at present exactly known. According 

 to Smith (1904), eucalyptus kinos contain two tannins giving with 

 ferric chloride a violet and a green reaction respectively ; the former 

 gelatinises readily but the latter does not. 



Uses. Red gum is not so powerful an astringent as kino, but its 

 action is said to be slower and more prolonged. 



BUTEA GUM 



(Bengal Kino, Buteae Gummi) 



Source, &C. Butea gum is the juice obtained by incising the stem 

 of Butea frondosa, Roxburgh (N.O. Leguminosce), dried. 



Description. The drug usually occurs in small, irregular, angular 

 fragments to one side of which dull, buff coloured portions of the cortex 

 and cortex of the stem sometimes adhere. When fresh it is ruby-red, 

 transparent in small fragments, and brittle ; but on keeping it becomes 

 dull, nearly black, opaque and tough. It is readily reduced to a reddish 

 powder and has an astringent taste. It is partially soluble in water 

 and in alcohol. 



