278 FRAGMENTS OF SCIENCE 



bonic acid given out. But the process did not end here. 

 After the oxygen had vanished, carbonic acid, in consid- 

 erable quantities, continued to be exhaled by the fruits, 

 which at the same time lost a portion of their sugar, be- 

 coming more acid to the taste, though the absolute quan- 

 tity of acid was not augmented. This was an observation 

 of capital importance, and Be'rard had the sagacity to re- 

 mark that the process might be regarded as a kind of 

 fermentation. 



Thus the living cells of fruits can absorb oxygen and 

 breathe out carbonic acid, exactly like the living cells of 

 the leaven of beer. Supposing the access of oxygen sud- 

 denly cut off, will the living fruit-cells as suddenly die, 

 or will they continue to live as yeast lives, by extracting 

 oxygen from the saccharine juices round them? This is 

 a question of extreme theoretic significance. It was first 

 answered affirmatively by the able and conclusive experi- 

 ments of Lechartier and Bellamy, and the answer was 

 subsequently confirmed and explained by the experiments 

 and the reasoning of Pasteur. Be'rard only showed the 

 absorption of oxygen and the production of carbonic acid ; 

 Lechartier and Bellamy proved the production of alcohol, 

 thus completing the evidence that it was a case of real 

 fermentation, 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 



