24S; ECONOMIC BOTANY. 



East in the sixteenth century. It is obtained mainly from 

 Gardnia Morella, a small tree belonging to the Gamboge 

 family (Guttiferce). It occurs in Ceylon, Siam, and 

 Cambodia, or Cambogia (whence the name). It has oppo- 

 site, entire leaves, and dioecious flowers. The yellow fruit, 

 or drupe, an inch or two in diameter, is pulpy and edible. 

 The resin Gamboge is obtained by making incisions into 

 the stem, out of which it flows. It is collected in wooden 

 vessels, as cocoa-nut-shells, bamboo-stems, etc. When 

 fresh, it is in color a light brownish-red, and lustrous ; 

 later it becomes brown, like liver, and lustreless. After 

 being exposed for a time it becomes coated with a green 

 layer. The streak is citron-yellow to orange. It has no 

 odor ; and the taste, though mild at first, becomes sharp 

 and biting. It is much heavier than water, having a spe- 

 cific gravity of over 1.2. Under the, microscope it is found 

 to be a homogeneous mass of gum, with granules of resin 

 embedded in it. A greater or less quantity of impurities, 

 as tissue, starch, etc., is present. The granules exhibit the 

 so-called Brownian or molecular movement very beauti- 

 fully. The gum in Gamboge is soluble in water, and the 

 resin is soluble in ether and alcohol. Both of the solu- 

 tions are tasteless. It is used extensively for coloring 

 alcoholic varnishes, for making varnishes for metals, and 

 it furnishes the yellow in water-colors. It is used also in 

 medicine. 



213. The drug Asafcetida is obtained from two species 

 of plants belonging to the Parsley family (UmhellifercB). 

 One, Seorodosma foelidum, growing between the Aral Sea ' 

 and the Persian Gulf, attains a height of six or seven feet, 

 and forms vast forests. It grows only in sandy soil. The 

 other plant is Narihex asafwiida of Afghanistan. It is five 



