(35 HISTORY OF THE GALLIC ACID. 



Examination of the Action of Caloric and of Water on Nut galls. 



Action of Caloric. 



Action of cal- Mr. Dcyeux having examined in a particular manner all the 

 products of the distillation of galls on a naked fire, I shall con- 

 sider only the acid liquor obtained from them. 

 Properties of The process was conducted in the manner indicated by that 

 flu1d djStlUCd enemist - The fluid in the receiver was aromatic, a little milky, 

 very acid, did not precipitate glue, and gave a violet blue with 

 sulphat of iron, which changed to a dirty green. Lime and 

 barytes produced a peach-blossom colour. Nitrat of mercury 

 threw down a blackish prcipitate; acetat of lead, and mufiat of 

 tin, a white. 

 Saturated with Having saturated the acid liquor with potash, I obtained by 

 gave signs of evaporation a brown empyreumatic matter, whichon the addition 

 -acetic acid. of sulphuric acid emitted a pungent smell resembling that of 

 acetic acid. 



Action of Water on Nut galls. 



Gall macerated Galls finely powdered being shaken in cold water for four 



in wattr. minutes, the liquor, when filtered, was of a golden yellow 



colour. One part was distilled in a retort on a sand heat : 



the other was saturated with carbonat of soda. 



Bistilled gave The produce of the distillation was a clear, colourless, and 



an acidulous slightly acid liquor, that precipitated neither glue nor sulphat 



of iron. 



.Saturated with The liquor saturated with the alkali was evaporated to dry- 



an a a i, sul- ness . anc j the residuum being dissolved in distilled water, 

 pnuric acid D * 



aidded and dis- sulphuric acid was added till it was a little in excess, when 



the mixture was distilled in a retort. The products were ex- 

 amined in succession. First a fluid came over without taste 

 or smell : soon after the liquor was acid, but contained neither 

 sulphuric nor gallic acid. 

 With boiling f made a similar experiment with boiling instead of cold 



water. The liquor remained turbid, though filtered. Being 

 subjected to distillation, and combined with soda, in the same 

 manner as the preceding, I obtained the same results. 



These 



