278 ■ STUDIES ox FERMENTATION. 



products. "\Ve could not say with certainty, from a purely 

 cliemical point of view, that we were dealing, fur example, with 

 an alcoholic fermentation, properly so called, and that the 

 veast of beer must be present in it, if we had not first deter- 

 mined the presence of all the numerous products of that 

 particular fermentation, and that they were present in those 

 proportions, characteristic of that fermentation under condi- 

 tions similar to those under which the fermentation in question 

 had occurred. In works on fermentation, the reader will often 

 find those confusions against which we are now attempting to 

 guard him. It is precisely in consequence of not having had 

 their attention drawn to such observations that some have 

 imagined that the fermentation in fruits, immersed in carbonic 

 acid gas, is in contradiction to the assertion which we originally 

 made in our Memoir on alcoholic fermentation, published 

 ill 1860, the exact words of which we maj^ here repeat : — " The 

 chemical phenomena of fermentation are related essentially to a 

 vital activity, beginning and ending with the latter ; we believe 

 that alcoholic fermentation never occurs " — we were discussing 

 the question of ordinary alcoholic fermentation produced by 

 the yeast of beer — " without the simultaneous occurrence of 

 organization, development, and multiplication of globules, or 

 c<:)ntinued life, carried on by means of globules already formed. 

 The general results of the present Memoir seem to us to be in 

 direct opposition to the opinions of MM. Liebig and Berzelius." 

 These conclusions, we repeat, are as true now as they ever 

 were, and are as applicable to the fermentation of fruits, of 

 which nothing was known in 18(>0, as they are to the fer- 

 mentation produced by means of yeast. Onl}', in the case 

 of fruits, it is the cells of the parenchyma that function as 

 ferment, h)/ a cojifi)iiiaf/oii of tlicir vital acfiviti/ in carbonic acid 

 (/as, whilst in the other case the ferment consists of the cells 

 of yeast. 



There should be nothing very surprising in the fact that 

 fermentation can originate in fruits and form alcohol, without 

 the presence of yeast, if the fermentation of fruits were not 



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