222 LIFE AND DEATH. 



phenomena. The boih'ng of the juice or the mash, 

 the heat given off by the copper, all this phenomenal 

 apparatus is but the consequence of the production of 

 the carbonic acid and of its liberations — i.e., the 

 consequence of the act of destruction of the sugar. 

 Here is organic destruction with its energetic 

 manifestations ! 



This example of the life of brewers' yeast, of the 

 saccharomyces, specially chosen by Le Dantec as 

 being absolutely clear and giving the best illustration 

 of his argument, contradicts him at every point. The 

 general thesis of this vigorous thinker is that we 

 cannot distinguish between the two parts of tlic vital 

 act, organic destruction, and assimilating synthesis ; 

 that these two acts are not successive ; that they give 

 rise to phenomenal manifestations equally evident, 

 apparent, or striking. Now, in the case of yeast, the 

 phenomenon of destruction is clearly distinct from 

 that of the assimilating synthesis which multiplies 

 the substance of the saccharomyces. In fact, the 

 action is realized by means of an alcoholic diastase 

 manufactured by the cell ; and Buchner succeeded in 

 isolating this alcoholic ferment which splits up the 

 sugar into alcohol and carbonic acid, and also in vitro 

 and in vivo, makes the vat boil arid heats the liquid. 

 All the yeast is at work at once, says M. Dantec. 

 No, and this is the proof. 



And, further, Pasteur himself, who had shown the 

 relation of the decomposition of the sugar to the fact 

 of the growth of the yeast and of the production 

 of accessory substances such as succinic acid and 

 glycerine, always referred to correlation between these 

 phenomena. The destruction of the sugar is the 

 correlative of the life of the yeast. This was his 



