ANALYSIS OF THE HUSKS OF WALNUTS. 37? 



Sulphate of iron gave the juice so deep a green, that USulphaieof 

 r ° iron, 



appeared black. No precipitation took jvlace, even on 



standing 6ome time, in consequence of the free acid found in 



the mixture, which is capable of imparting a fine gray to 



wool or silk. 



~ , , . . ,. . , ,, r i» Oxal. of am- 



Oxalate of ammonia indicated the presence ot lime. m onia. 



Nitrate of barytes produced no signs of any sulphate. Nitr.©fbarytes> 

 Nitrate of silver acts on it in a manner well adapted to andof s i lvtJ - 

 reveal the presence of the alterable hydroearburet radical, 

 for it produces a pretty copious precipitate, which quickly 

 becomes coloured ; while the silver resumes its metallic 

 lustre from the action of the vegetable substance on the 

 oxigen of the oxide. The precipitate is then no longer 

 soluble but in part in nitric acid, and leaves charcoal as a 

 residuum. 



Alkalis change the juice to a deep red, and form in it Alkalis, 

 precipitates that contain lime. If after a certain time an 

 acid be poured into the liquor, another flocculent sediment 

 is produced, which dries, grows black, has a vitreous frac- 

 ture, and resembles in its nature the pellicles, that are 

 formed successively on the surface of the juice exposed to 

 the air. 



Acetate of lead occasioned in the juice a whitish, floccu- Acetate oflea<L 

 lent, very copious precipitate, which dissolved entirely in 

 distilled vinegar. This precipitate, being decomposed by 

 sulphuretted hidrogen, yielded a coloured liquor, of con- 

 siderable sourness mixed with astringency ? which produced 

 a sediment with gelatine, and with acetate of lead a pre- 

 cipitate soluble in vinegar. This acid, being evaporated by 

 a gentle heat, yielded small, ill-defined crystals, immersed 

 in the uncrystallizable liquor. The whole was mixed with 

 carbonate of lime ; and after the mixture, which contained 

 an excess of acid, had been heated, I filtered it. By eva- 

 porating I obtained a granular, coloured substance, formed 

 by the union of a number of small acicular crystals. This 

 salt, being treated with cold water, dissolved in it in part: 

 and the solution, evaporated to dryness, left a brown var- 

 nished residuum, which comported itself like malate of 

 lime, retaining some tannin, which then precipitated iron of 

 a blackish blue. The portion of the calcareous salt that 



would 



