3^g analysis of the husks of walnuts. 



■would not dissolve in cold water was treated with diluted 

 sulpuric acid, which separated from it citric acid, still con- 

 taminated with malic. 



Subacetateof The juice thus freed from part of the matters if held in 

 solution was still coloured. Acetate of lead supersaturated 

 with oxide produced in it another sediment, and rendered 

 the supernatant liquor nearly colourless. This sediment 

 yielded on analysis the same products as above ;' namely 

 malic acid, colouring matter, and tannin, which had escap- 

 ed the first precipitation in consequence of the presence 

 of the acetic acid, that had become predominant in the 

 liquor. 



Examination of The magma left after expression of the juice, after hav- 

 e magma. jng been treated with alcohol, which extracted from it some 

 green resinous matter, was heated with water till it boiled, 

 to free it from the starch and the coloured matter it re- 

 tained. When thus exhausted, it was digested with dilute 

 nitric acid, which separated some phosphate and oxalate of 

 lime, that had been precipitated from the acid liquor by 

 ammonia. The means I employed to separate these two 

 earthy salts, which are very frequently associated together 

 in vegetables, are founded on the property distilled vinegar 

 diluted with water has of dissolvirtg phosphate of lime, with- 

 out sensibly affecting the calcareous oxalate. 



Distilled water Though the husk has a peculiar smell, it afforded nothing 

 very remarkable by distillation in a water bath. I obtained 

 only a liquor with a faintish taste, which, instead of com- 

 ing over limpid, was brownish ; and on its surface were 

 perceptible slight iridescent pellicles, which sunk to the bot- 

 tom in the form of a sediment. 



Ashes. The husk yielded by incineration potash, carbonate of 



lime, phosphate of lime, and oxide of iron. 



From this examination it appears, that the fleshy cover- 

 ing of the walnut contains: 



Substances'con- 1st, Starch : 



tainedinthe 2d, An acid and bitter substance, very alterable, which 



appears to approach ^the state of charcoal by the contact 

 of air : 



3d, malic acid : 

 4th, tannin -. 



5th, citric 



