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XXXIII. On the Question, Whether Alcoholle a Product of 

 Fermentation, or of Distillation P By M. Donovan*. — 

 [Read to the Kirivanian Society ofDiibUn, May 29, 1813.) 



JL HE intoxicating property of fermented liquors h^sbeen known 

 to mankind from the remotest ages of antiquity. For a series 

 of centuries nothing of their nature was regarded ftirther than 

 their agreeable taste and exhilarating eiTects : and of the person 

 who first separated alcohol from them, nothing at this distance 

 of time can be certainly known. When, however, alcohol had 

 been obtained, it was discovered that it possessed an intoxicat- 

 ing power in a greater degree than the original liquor ; and that 

 the residuum of the operation no longer produced even exhilara- 

 tion. Hence, by a simple and natural process of reasoning, it 

 was inferred that alcohol is the true intoxicating portion, and 

 that fermented liquors owe their influence entirely to its pre- 

 sence. Accordinglv, we find tliis opinion to have been received 

 without alteration until the days of Rouelle the elder. This 

 philosopher, observing that, in the distillation of wine, no spirit 

 appears until the temperature is raised to boiling, suggested 

 that alcohol does not exist in wine completely formed, and that 

 it does not assume a distinct existence until a sufficiently high 

 temperature be applied. In support of this opinion he adduced 

 no other evidence ; and the suggestion, although admitted by 

 some, perhaps without much examination, seemed to have ob- 

 tained no particular attention until in 1785 it was revived and 

 somewhat new-modelled by Fabroni, a Florentine philosopher. 

 In a memoir which obtained the prize from the Academy of 

 Florence, Fabroni asserted that chemists had been much de- 

 ceived in supposing that alcohol is a product of fermentation. 

 He stated that when he added a small quantity of alcohol to 

 new wine, he could by saturation with potash separate precisely 

 the quantity added, and no more ; while, when the experiment 

 was niade with new wine, to which no alcohol had been pre- 

 viously added, not a trace of the latter could be perceived, al- 

 though by distillation 25 per cent, might be obtained. Hence 

 he thought he had a right to conclude, that alcohol is not con- 

 tained in wine ; that it is formed from the elements of wine 

 by the operation of fire : in a word, that it is a product and 

 not an educt of distillation. In further support of this opinion 

 he stated, that when wine is distilled, and when the distilled 

 liquor is mixed with the residue, wine is not reproduced. He 

 allowed that a little alcohol may be found in old wines ; but he 

 accounted for this by supposing that lapse of time and the na- 



* Communicated by tlie Autli6r. 



tural 



