THE HEASON WHY. 3J7 



To every thing there is a season, and a time to every purpose under heaven." 



ECCLESIASTES III. 



pomegranate, but the great majority from Western Asia, as the orange, fig, 

 cherry, peach, apricot, apple, and pear. A variety of the plum, the damson, or 

 damascene, came from the neighbourhood of Damascus during the Crusades. 

 The name of the damask-rose points to the importation of the plant from th 

 same quarter into Europe. 



The ocean as well as the land has different botanical regions j and changes 

 of the vegetation are observed with the depth analogous to the variations of 

 terrestrial plants with the height. Marine vegetation seems to have its vertical 

 extent determined by the range of light in water, which varies with the 

 power of the sun and the transparency of the water. 



CHAPTER LXIII. 



1254 What are vegetable gums ? 



Vegetable gums are secretions of plants which are generally 

 toluble in water, and which subserve various useful purposes. 

 Gum Arabic is one of the most important of this class of vegetable 

 productions. 



Gutta-percha is an invaluable substance lately added to 

 the list of known vegetable productions. It is obtained by 

 cutting the bark of trees of the class called Sapotacea. Its 

 proper name is gutta Pulo Percha, gutta meaning gum, and Pulo 

 Percha is the island whence it is obtained. But gutta-percha is 

 not, strictly speaking, a gum. 



India-rubber is also a vegetable secretion, improperly called 

 elastic gum. It is obtained from the milky juice of various trees 

 and plants, especially from the syringe tree, of Cayenne. 



1255. What are vegetable resins ? 



Vegetable resins are derived from the secretions of plants, and 

 are generally distinguished from gums by being insoluble in 

 water, but being soluble in spirits. 



When one of these substances is soluble in either water or spirit* 

 it is called a gum-resin. 



1256. What are vegetable acids ? 



Vegetable acids are chiefly obtained from fruit ; but also abut 

 dantly from wood, by distillation. 



