208 On the Chemical and Natural History of Lupuline. 



theu treated with sulphuric acid dik^ted with its weight of 

 water or with gelatinous phosphoric acid, yields some sul- 

 phate or phosphate of soda which remains in solution in the 

 aqueous liquid, to the surface of which is seen to float a 

 hrown oily liquid, diffusing a strong and disagreeable odour 

 of butyric and valerianic acids. 



Subjected to distillation this liquid furnished, by many 

 successive rectifications, a product which boiled at + 175 

 degrees (= 347° Fahr.), and distilled without alteration at 

 this temperature ; the first portions carried over water in 

 excess, which was thus separated with sufficient ease. 



This acid, obtained in a state of purity, is a liquid, 

 slightly oleaginous, very fluid, colourless, with a strong and 

 persistent odour of valerianic acid ; its flavour, is acid and 

 piquant ; it produces a white stain on the tongue in the 

 manner of energetic fatty acids ; it is not solidified by a 

 cold of —16 degrees (=+3°-2 Fahr.), and remains per- 

 fectly limpid ; it burns readily with a smoky flame. The 

 specific gravity of this acid is found to be 0'9403 at + 15 

 degrees ( = 59° Fahr.). It corresponds to that of valerianic 

 acid, which has been found to be 0*937 at + 16'5 ( = 61''-7 

 Fahr.) 



I omit here the description of all the analyses which I 

 have made for ascertaining the composition of this acid. 

 All lead to the formula of valerianic acid. I have pur- 

 posely multiplied its combinations with oxide of copper, 

 oxide of silver and baryta, in order to be well satisfied of 

 its true constitution. But the odour alone of lupuline, 

 especially of that which has been kept for some time, does 

 not admit of doubt of the existence of this acid among the 

 bodies whicli this substance contains. 



Volatile Oil of Lupuline. 



This crude essential oil — that is to say, such as has been 

 given by distillation of lupuline with water — is an oleagin- 

 ous liquid, more or less fluid according to the state of the 

 lupuline which furnished it, and of a specific gravity less 

 than that of water. It has at the same time a somewhat 

 intense colour of yellowish green, more frequently of a 

 beautiful green ; its odour recalls slightly that of the hop ; 



