118 STUDIES ON FERMENTATION. 



Our experiments were conducted in the following manner : — 

 In some flat porcelain basins, we grew some pure mycoderma 

 rini * on fermented liquids, such as wine or beer, or on arti- 

 ficially vinous liquids, such as alcoholized yeast-water, taking 

 care to boil these liquids previously to kill any germs of yeast 

 or other organism that they might contain. The basins them- 

 selves, as well as the plates of glass with which they were to be 

 covered, were plunged into boiling water just before they were 

 wanted for use. As soon as the film of mycoderma had become 

 well developed and thick, and even wrinkled — a process requir- 

 ing not more than two or three days during summer heat — we 

 decanted the subjacent liquid, by means of a siphon, so as to 

 leave the film on the bottom of the basin. We then diffused 

 the whole mass of efflorescence in a saccharine liquid that had 

 been boiled and afterwards cooled down in a closed vessel ; 

 generally, we used wort or must preserved by Appert's process. 

 After that, we emptied the mixture of saccharine liquid and 

 efflorescence into long-necked flasks that had likewise been 

 previously heated, as also had the funnels used in the process of 

 transference. 



It seemed to us that experiments conducted with all these 

 precautions must be free from causes of error. It was true that 

 we were working more or less in contact with atmospheric air, 

 but all that we had to fear for the soundness of the conclusions 

 which we might draw was the presence of germs of alcoholic 

 ferment, and we considered how few of these there are amongst 

 floating particles of dust. Consequentl}^ if we succeeded in 

 observing the advent of yeast in each of the long-necked flasks, 

 accompanied by an active alcoholic fermentation, we thought 

 that we might, without danger of error, admit as a fact the 

 transformation of cells of mj^coderma into cells of yeast. 

 Again, we thought that we should probably find in the forms of 

 the cells of yeast which were directly derived from the cells of 



* We secured the purity of our mycoderma by the same means that we 

 have already described for the procuring of spores oi peniciUium or other 

 fungoid growths in a state of purity. 



