STUDIES ON FERMENTATION. 117 



one of the common moulds, yet we did believe in its transforma- 

 tion into alcoholic ferment. In the course of more elaborate 

 researches, however, we at last discovered that our previous 

 experiments had been vitiated from the same source of error 

 which we have so often had occasion to point out as affecting 

 the observations of our opponents, namely, the fortuitous and 

 spontaneous introduction, unknown to the experimentalist, of 

 germs of the very plant for whose appearance by way of 

 transformation he is seeking. 



When we consider that every fermented vinous liquor, when 

 put on draught, is liable to efflorescence, it is difficult to avoid 

 the supposition that this efflorescence is primarily due to cells 

 of the yeast that has caused the liquid to ferment, from which 

 cells the liquid could not be completely freed, no matter how 

 bright it might have been, and which come to the surface of 

 the liquid to live after the manner of fungoid growths. "We 

 wished to test this supposition by means of experiments. So 

 great, however, was the resemblance between tlie forms possible 

 to yeast and mycoderma, of which latter efflorescence is really 

 composed, that we quite despaired of being able to solve the 

 question by microscopical examination, that is, by observing the 

 actual conversion of a cell of yeast into a cell of mycoderma. 

 In order, then, to overcome that difficultj'^, we endeavoured to 

 produce an inverse transformation — that of mycoderma into 

 yeast. We imagined that we should doubtless obtain this 

 result by submerging some of the efflorescence of wine or beer 

 in a saccharine liquid well adapted to alcoholic fermentation. 

 By submerging the mycoderma we would do away with the 

 ordinary conditions of life in this kind of fungoid growth ; for 

 we would thus prevent the supply of oxygen from the air, since 

 that oxygen would always be excluded, in the most effectual 

 manner possible, by the portion of mycoderma that would 

 remain on the surface of the liquid, even after the submersion 

 process ; and on the other hand, we would be subjecting our 

 growth to the ordinary conditions of ferment life, which acts at 

 the bottom or in the bulk of liquids fermenting. 



