220 PASTEUR : THE HISTORY OF A MIND 



ordered in all haste several hothouses with the intention 

 of transporting them into the Jura, where I possess a 

 vineyard some dozens of square meters in size. There 

 was not a moment to lose. And this is why! 



"I have shown, in a chapter of my Etudes sur la biere, 

 that germs of yeast are not yet present on the grape 

 berry in the state of verjuice, which, in the Jura, is at 

 the end of July. We are, I said to myself, at a time of 

 year when, thanks to a delay in growth due to a cold 

 rainy season, the grapes are just in this state of verjuice 

 in the canton of Arbois. By taking this moment to 

 cover some vines with hothouses almost hermetically 

 closed, I would have in October during the grape har- 

 vest, vines bearing ripe grapes without any yeasts of 

 wine on the surface. These grapes, being crushed with 

 the precautions necessary not to introduce germs of 

 yeast, will be able neither to ferment nor to make wine. 

 I shall give myself the pleasure of taking them to Paris, 

 of presenting them to the Academy, and of offering some 

 clusters to those of my confreres who may still believe 

 in the spontaneous generation of yeast. 



"The fourth of August, 1878, my hothouses were 

 finished and ready to be put up. The work of setting up 

 and of putting in the glass was finished in a few days. 



" During and after the installation of the hothouses, 

 I searched with care to see if the germs of yeast were 

 really absent from the clusters in the state of verjuice, 

 as I had found hitherto to be the case. The result was 

 what I expected; in a great number of experiments I 

 determined that the verjuices of the vines in the canton 

 of Arbois and notably those of the vines covered by the 

 hothouses, bore no trace of germs of yeast at the beginning 

 of the month of August, 1878." 



"In the fear that an insufficient sealing of the hot- 

 houses would allow the germs to reach the clusters, I 



