GALLIC ACID, 301 



The existence of an uncombined acid in galls and 

 various other astringent substances was suspected by 

 Macquer, Lewis, Monnet, and other able chemists. 

 It was not, however, well examined until 1772, 

 when Morveau and the other Dijon academicians 

 took the subject under consideration. These scien- 

 tific men, however, brought forward no unanswerable 

 proof, and the matter remained in this state until 

 1780, when Scheele put the question beyond all 

 doubt, by publishing a method of separating the acid 

 from the other constituents of the gall-nut. 



Gallic acid is soluble in ten parts cold water, and 

 three of boiling water. 



This acid is used in the art of dyeing, especially in 

 the formation of a black dye ; and is employed to fix 

 or improve several other colours. 



2 D 



