BLACK DYES. 411 



kernel ; this may already have been devoured by the 

 insect, who has pierced its way back to liberty. The 

 gall-nut is certainly very different to the excrescence 

 called the oak-apple, found on oaks, and which is 

 apparently produced from the puncture of an insect. 



All galls present a tuberculous, uneven, globular 

 surface, but they differ very much from each other in 

 size and colour; some not being larger than the 

 smallest hazel-nut, arid others about the size of a 

 walnut, from which however they differ in shape. 

 Their colour varies, some having a tinge of blue, 

 some of green, and others of a pale yellow approaching 

 to white. They are known and distinguished in 

 commerce by these different colours, blue-galls being 

 the most esteemed. The best of these are now 

 brought from the East Indies, which obtain a higher 

 price than those received from Turkey. The average 

 annual importation for the five preceding years was 

 1,936 bags and chests; each of the former weighing 

 1 cwt. and of the latter from 2 to 3 cwt. The 

 average price of the best, during that period, has 

 been k. 15s. per cwt. They are admitted at a duty 

 of 5.9. per cwt. 



The constituent parts of galls, wherein their 

 usefulness in the arts consists, have been noticed 

 when treating of tanning and of the acids. 



The cups of the acorns of the Velani oak, or 

 Quercus cegilops, are found to partake of the nature 

 of the gall-nut, and are much .used in this country as 

 a less expensive substitute. In China they have 

 been long applied to the same purpose*, and Olivier 

 remarks that other Orientals and the Italians likewise 

 are acquainted with their use, but that the French 

 have hitherto neglected to employ this substance. 



* Staunton's Embassy to China. 



