ORIGIN OF THE YEASTS OF WINE 223 



experiment we may take these samples of earth at a 

 considerable distance from the surface, even from a depth 

 of 10 to 15 centimeters. Still more frequent in this 

 kind of experiment, is the alcoholic fermentation by 

 yeasts of the genus Mucor, so abundant in cultivated 

 soil are the spores of these little plants. 



"I have had the curiosity to compare the soil of the 

 vineyard and that covered by my hothouses with 

 regard to the presence of the spores of grape yeasts and 

 the spores of Mucor. But, although the experiment 

 has been made a great number of times, I have never 

 seen produced in my tubes with the soil from my hot- 

 houses, the alcoholic fermentation due to the alcoholic 

 yeasts of the grape; very frequently there appears, 

 on the contrary, the fermentation due to the yeast of the 

 Mucor. 



"How many reflections these results lead to! Can we 

 fail to observe that the further we penetrate into the 

 experimental study of germs, the more we see therein 

 unexpected lights and just ideas leading to knowledge 

 of the causes of contagious diseases! Is it not worthy 

 of attention that in this vineyard of Arbois, and this 

 would be true of the millions of hectares of vineyards 

 all over the world, there was not, at the time when I 

 made these experiments which I have just described, 

 a particle of soil, so to speak, which was not capable 

 of provoking the vinous fermentation, and that, on the 

 contrary, the soil of the hothouses of which I have spoken 

 was unable to do this. And why? Because, at a defi- 

 nite moment, I covered this soil with some glass. The 

 death, if I dare to speak thus, of a grape berry which 

 has been thrown on the ground of any vineyard, will 

 be, somehow or other, infallibly accomplished by the 

 yeast parasites of which I speak; but this kind of death 

 will be impossible, on the contrary, in the little corner 



