450 Chemical Analysis of the Green Shell of the Walnut. 



juice of a deep red, and produce precipitates which contain 

 lime. If at the end of a certain time an acid is poured upon, 

 the liquor, another flocculent precipitate tal^es place, which 

 when dried hecomes black, vitreous in its fracture, and ap- 

 pears of a similar nature with the pellicles which are formed 

 on the surface of the juice exposed to the air. Acetate of lead 

 produced from the juice a flocculent precipitate of a whitish 

 colour, and verv abundant, entirely soluble in distilled vi- 

 negar. This precipitate, decomposed by sulphuretted hy- 

 drogen, afforded a coloured liquor of a very strong acid 

 taste, combined with austercne&s 5 a sediment was produced 

 in it by gelatin, and with acetate of lead it gave a precipi- 

 tate soluble in vinegar. This acid of walnut, submitted 

 to a gentle heat, afforded some snjall imperfect crystals 

 swimming in an uncrvstallizable liquor : the whole was 

 mixed with carbonate of lime, and after having heated the 

 mixture, which contained an excess of acid, it was filtered. 

 T obtained bv evaporation a thick coloured mass formed by 

 the union of a number of small acicular crystals : this salt, 

 treated with cold water, was parllv dissolved by it; the solu- 

 tion, evaporated to drvnessjleft a brown residue like varnish, 

 with the same habitudes as nialate of lime, holding some 

 tannin, which precipitated iron of a blackish-blue colour. 

 That portion of the calcareous salt which was not dissolved 

 in the cold water, was treated by weak sulphuric acid, which 

 separated from it some citric acid still contaminated by 

 malic acid. 



The juice of the walnut shell thus freed from a part of 

 the substances it held in solution was still coloured; the 

 superacetate of lead produced another piccipitate from it, 

 and rendered the supernatant liquor nearly colourless: this 

 precipitate furnished by analysis the same products obtained 

 above, viz. malic acid, colouring rnatter and tannin, which 

 had escaped the fir« precipitation on account ot the pre- 

 sence of the acetic acid which was predominant in the lit 

 quor. 



The faeces remaining after the expression of the juice 

 ■were infused in alcohol, which extracted from them a green 

 resinous matter ; they were then boiled in water to free them 

 from the starch and colouring matter which were contamed 

 in them : thus prepared, they were digested in weak nitric 

 acid, which separated phosphate and oxalate of lime: these 

 were precipitated from the acid liquor by ammonia. 'J'he 

 method I employ lo obtnin separately these two earthy salts. 

 so often combined in vegetables, is founded upon the pro- 

 perty 



