GUM TRAGACANTH, 243 



it absorbs largely, but is insoluble; the finest qualities 

 contain more of the former, and the inferior more of the 

 latter principle. 



The quantity imported of all of the above kinds of gum 

 is very considerable; in 1850, 1984 tons, of which 328 

 tons were Gum Senegal. These gums are chiefly used by 

 the manufacturers of silks, crapes, muslins, etc., for the 

 purpose of stiffening and glazing their fabrics; there are 

 besides various other economic purposes to which they are 

 applied. Gum arabic is said to be so nutritious as food, 

 that the Arabs who gather this gum almost support them- 

 selves with it during the harvest. 



Gum Tragacanth, or Gum Dragon. — An exudation 

 from the stems of two or three species of Astragalus, 

 another genus of the Natural Order Leguminosce. 



Tragacanth was known to the ancients, and was by them 

 called rparydfcavOa ; it does not form in tears like the gums 

 previously described, but forms in flakes, which have the 

 appearance of paste forced through narrow splits in the 

 bark. It is white and opake, and the flakes have a curled 

 and twisted appearance. 



The best tragacanth is said, upon good authority, to be 

 the produce of Astragalus gummifer, a native of Koordistan ; 



