A YIMOUS SMELL. 333 



In the same manner a ferment oil has been ob- 

 tained from the leaves of the Quercus robur, having 

 an agreeable odour and a specific weight of 0*795. 

 Bley prepared another ferment oil out of herba 

 millifolii, having properties differing from that pre- 

 pared from the fresh herb. 22 Dutch Ib. gave 20 

 grammes ; another kind of oil was obtained from 

 herba echii, 24 Dutch Ib. yielding 80 grammes. 

 Another from Urtica urens, loth (i oz.) from 46 Ib. 

 of the herb in blossom. One also from the leaves of 

 Salix, Plantago, and Chaerophyllum sylvestre. 



All these ferment oils have a strong odour. 



According to Rossignon, from the pressed juice of 

 reinettes and other apples, a ferment oil is obtained 

 which smells like musk. 



The production of volatile aromatic substances by 

 the fermentation of plants is universal, and the 

 grape skins are perhaps as well suited to produce it 

 as the constituents of the grape juice itself. But no 

 satisfactory examination has been made with respect 

 to grapes. At any rate these ferment oils deserve 

 to be compared with the fusel oils. 



The following observation deserves consideration in 

 so far as it concerns the bouquet of wine. If aromatic 

 wine be distilled out of a retort a brandy is obtained 

 having a pleasant smell, but which will never have 

 the smell of wine. However fragrant the wine may 

 have been, that which remains in the retort after dis- 

 tillation will always smell disagreeably of cenanthic 



