FERMENTATION. 265 



extracting oxygen from the saccharine juices round 

 them ? This is a question of extreme theoretic signi- 

 ficance. It was first answered affirmatively by the 

 able and conclusive experiments of Lechartier and 

 Bellamy, and the answer was subsequently confirmed 

 and explained by the experiments and the reasoning of 

 Pasteur. Berard only showed the absorption of oxygen 

 and the production of carbonic acid ; Lechartier and 

 Bellamy proved the production of alcohol, thus com- 

 pleting the evidence that it was a case of real fermen- 

 tation, though the common alcoholic ferment was absent. 

 So full was Pasteur of the idea that the cells of a fruit 

 would continue to live at the expense of the sugar of 

 the fruit, that once in his laboratory, while conversing 

 on these subjects with M. Dumas, he exclaimed, ' I will 

 wager that if a grape be plunged into an atmosphere 

 of carbonic acid, it will produce alcohol and carbonic 

 acid by the continued life of its own cells that they 

 will act for a time like the cells of the true alcoholic 

 leaven.' He made the experiment, and found the result 

 to be what he had foreseen. He then extended the 

 enquiry. Placing under a bell-jar twenty-four plums, 

 he filled the jar with carbonic acid gas ; beside it he 

 placed twenty-four similar plums uncovered. At the 

 end of eight days, he removed the plums from the jar, 

 and compared them with the others. The difference 

 was extraordinary. The uncovered fruits had become 

 soft, watery, and very sweet ; the others were firm and 

 hard, their fleshy portions being not at all watery. They 

 had, moreover, lost a considerable quantity of their 

 sugar. They were afterwards bruised, and the juice 

 was distilled. It yielded six and a half grammes of 

 alcohol, or one per cent, of the total weight of the 

 plums. Neither in these plums, nor in the grapes first 

 experimented on by Pasteur, could any trace of the 



