94 ACACIA SENEGAL 



4. Morocco, Mogador, or Brown Barbary Gum. The botanical 

 source of this gum is supposed to be Acacia arabica, Willd. It 

 is usually of a brownish colour, and is found either in small, 

 angular, mostly broken pieces ; or in tears, which when per- 

 fectly dry are permeated by cracks like Turkey gum, and very 

 brittle. 



5. Gape Gum. This is principally derived from Acacia horrida, 

 Willd. It is in small fragments of an amber-brown colour, and 

 is regarded as a very inferior kind of gum. 



6. East India Gum. This gum is the produce of Acacia 

 arabica, Willd., and other species of Acacia. It is principally 

 imported from Bombay, hence its name ; but it is almost entirely 

 the produce of Eastern Africa. It varies very much in its appear- 

 ance, and is commonly mixed with other gums ; it is regarded as 

 a very inferior kind. 



7. Australian or Wattle Gum.. This is the produce of various 

 species of Acacia, thus, according to Fliickiger and Hanbury, 

 of A. pycnantha, Benth. ; A. decurrens, Willd. ; A. dealbata, 

 Link. ; and A. homalophylla, A. Cunn. It is found com- 

 monly in large tears or masses, of a dark yellow or reddish- 

 brown colour. This gum, which has a transparent appearance, 

 being nearly free from cracks or fissures, is said to be readily 

 soluble in water, and to form a very adhesive mucilage. It 

 is frequently contaminated with pieces of the astringent barks 

 of the trees from which it is obtained ; hence its solution unless 

 carefully prepared, will frequently contain some tannic acid. 



It will be seen from the above general notice of the varieties 

 of gum that they vary much in_ their characters, and that the 

 Kordofan or Turkey Gum is the finest kind. The characters 

 and tests of good gum are given in the British Pharmacopoeia as 

 follows : " In spheroidal tears usually from half an inch to an 

 inch in length, nearly colourless, and opaque from numerous 

 minute cracks, or in fragments with shining surfaces ; brittle ; 

 bland and mucilaginous in taste ; insoluble in alcohol, but soluble 

 in water. The aqueous solution forms with subacetate of lead an 

 opaque white jelly. If an aqueous solution of iodine be added to 



