318 SUBSTANCES FOUND TO POSSESS 



of oananthic ether by means of the oenanthic acid in 

 wine seems to me, however, not improbable, as in 

 proportion to the formation of acetic and compound 

 ether (of which we have still to treat) in old wine 

 will be the diminution of osnanthic ether. The aroma 

 increases, and the disagreeable odour decreases. 



The formation of acetic acid and acetic ether in 

 wine may, however, be very different. 



Among the volatile substances which may exist in 

 wine is one which, on several accounts, deserves to be 

 mentioned here. It is ISTollner's aceto-butyric acid, 

 which has been examined in detail by Mckles.* 



JSTollner prepared this acid from raw tartar, which 

 he boiled with water and hydrated lime, decomposing 

 the neutral tartrate of potash with gypsum, in order 

 to procure tartrate of lime. After filtering the liquid, 

 he mixed the tartrate of lime which had been obtained 

 (and which contained the organic matter of wine fer- 

 ment) with water, and placed it in the sun.f Carbonic 

 acid and a soluble lime-salt were developed, out of 

 which by sulphuric acid a volatile acid was separated, 

 which quickly resolved itself into butyric and acetic 

 acid, but according to Nickles, should be called a 

 peculiar compound of both acids = C 6 H 5 O 3 , HO, a 

 compound like that of the metacetonic acid, but with 

 quite different properties. 



The examination instituted by Nickles renders it 



* Liebig's Ann. Bd. 61, s. 343. 



t Berzelius, Lehrbuch der Chemie, 5 Aufl. Bd. 4, s. 256. 





