BLACK DYES. 



409 



Oak Galls. Quercus tinctoria. 



whether this insect really produces the excrescence 

 by wounding the bark, or whether it preys upon ttye 

 fruit of the tree. Mr. Aikin observes, " that not- 

 withstanding" the concurrent testimony as to the 

 origin of the gall-nut, any person who will give him- 

 self the trouble to break half a dozen somid unper* 

 forated Aleppo galls may readily convince himself 

 that this is one of those vulgar errors which are 

 repeated and believed from generation to generation, 

 because in philosophy and natural history it is easier 

 to believe than to examine *." 



The gall-nut consists of four distinct parts, having 

 every characteristic appearance of some other kinds 

 * Aikiu's Chemical Dictionary. 



2 N 



