NINETEENTH-CENTURY MEDICINE 



to be desired, much or little, according to the abun- 

 dance and the character of these little germs. More- 

 over, when a finished beer of good quality loses after a 

 time its agreeable flavor and becomes sour, it can be 

 easily shown that the alcoholic yeast deposited in the 

 bottles or the casks, although originally pure, at least 

 in appearance, is found to be contaminated gradually 

 with these filiform or other ferments. All this can be 

 deduced from the facts already given, but some critics 

 may perhaps declare that these foreign ferments are the 

 consequences of the diseased condition, itself produced 

 by unknown causes. 



" Although this gratuitous hypothesis may be diffi- 

 cult to uphold, I will endeavor to corroborate the pre- 

 ceding observations by a clearer method of investiga- 

 tion. This consists in showing that the beer never has 

 any unpleasant taste in all cases when the alcoholic 

 ferment properly so called is not mixed with foreign 

 ferments ; that it is the same in the case of wort, and that 

 wort, liable to changes as it is, can be preserved unal- 

 tered if it is kept from those microscopic parasites which 

 find in it a suitable nourishment and a field for growth. 



" The employment of this second method has, more- 

 over, the advantage of proving with certainty the 

 proposition that I advanced at first namely, that the 

 germs of these organisms are derived from the dust of 

 the atmosphere, carried about and deposited upon all 

 objects, or scattered over the utensils and the materials 

 used in a brewery materials naturally charged with 

 microscopic germs, and which the various operations 

 in the store-rooms and the malt-house may multiply 

 indefinitely. 



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