q4 history of the oallic acid; 



alkalies, This solution takes a colour more or less green with carbonat 



of soda, but is not changed by carbonat of ammonia. Caustic 

 potash changes it to a deep brown ; and ammonia to a reddish 

 brown. 



ailphat of iron, With green sulphat of iron it is a violet blue, which is constant, 



"ry 1 ° f mCr " aS an excess does not alter iU Wilh nitrat ° f mcl ' cur y n S ivcs 



acetat of lead, a yellow precipitate; with acetat of lead, and muriat of tin, a 

 munatoftin, ^ 



©xigenized nm- The solution of this acid is not altered in appearance by ox- 



Caci ' igenizcd muriatic acid, 

 and glue. With glue it gives a copious precipitate. 



Xichter's acid. The same experiments wen: made with the acid obtained by. 

 - Rich ter's process, and the results were similar, except that the 

 precipitate thrown down by glue was very abundant. 

 Solution of sub- Sublimed acid of Deyeux. The solution of this acid by hot 

 ime aeid, water em ; ts an aromatic odour, and a slight oily pellicle is per- 

 ceptible on its surface. 



This solution becomes brown by exposure to the air. It 

 with lime- faintly reddens tincture of litmus : limewater gives it a colour 



water, Q f w j nc | which an excess of it converts to a fawn colour. 



fcarytes, 7 



With barvtcs we obtain the latter tint, and the liquor is imme- 

 diately covered with an oily pellicle. 



carbonated Carbonat of ammonia produces no change in the acid liquor; 



a that of soda gives it a fawn colour. 



pure alkalies, Caustic potash browns it considerably: with ammonia (he 

 colour is lighter. 



sulphat of iron, If a few drops of asoliitioriof sulphat of iron be dropped 

 into this acid liquor, a blue colour is produced, which soon 

 changes to a violet blue. Frequently however, instead of a blue 

 colour, we have a deep green. This no doubi depends on some 

 peculiar circumstances: and I conceive it may be, attributed 

 to the degree of oxidation of the iron; for with muriat of iron 

 at a maximum we have constantly a green colour. This effect 

 is less striking with other acids: the infusion of galls, made 

 without lead, always retains its pure blue colour. 



Willi nitrat of mercury the precipitate is blackish: that with 



nitrat of Bier- acetat of lead id fawn coloured, and very light. 



cury, acetat of qq ie sulplui-Ts pf zinc and copper, and muriat of tin, produce 



other metallic no change. 



M,ti) ' Oxigen- 



