2 g 4 THE OLIVE LEAF. 



CHAP. 



leaves that had been blackened and curled up by 

 the action of fire. They contrasted very strikingly 

 with the tender spring foliage sprouting by their side. 

 These were the empty nests of a species of green aphis, 

 in which the young had been hatched the preceding 

 autumn. In Persia, China, and along the Levant this 

 most remarkable gall used to be employed, under 

 the name of " baizonges," to assist in extracting the 

 scarlet dye from the cochineal insect. It contains a 

 liquid formerly greatly in demand for curing wounds, 

 under the name of "Oil of St. John." The astringent 

 quality and viscidity of the fluid may have had some 

 healing effects, and beneficially excluded the air from 

 open wounds. But the most important of all the 

 species is the common gall-nut of commerce, which 

 grows on a kind of shrubby oak seldom exceeding six 

 feet in height, found abundantly in the Levant. The 

 galls are hard woody and heavy, about the size of a 

 marble, usually round and studded with protuberances. 

 The best are those which are gathered before the 

 departure of the insect, because they are heavier and 

 contain more of the tannin principle. They have a 

 bluish colour; whereas those that have been left by 

 the insect are whitish, light, and pierced by a little 

 round hole. They are perfectly astringent, and are 

 frequently employed in medicine and also in dyeing, 

 while they form an essential ingredient in making ink. 

 It is strange to think that to the nest of an insect 

 we are indebted for the prime element of literature 

 and of written thought. The words which I have 



