16 1 STllHES ON FERMEXTATIOX, 



yeast ? The following experiments were undertaken to 

 dotermme this point. 



We have just seen that on October 2 fragments of the woody 

 peduncles introduced with must, on the spot, caused that must 

 to ferment in seven cases out of twelve. In order that we 

 misrht test the wood of these same bunches durino' winter we 

 took care to wrap some fragments up in paper previously passed 

 through the flame. We afterwards took occasion to test 

 portions of these fragments as follows : — 



On December 21st, 1875, we conducted an experiment with 

 twelve. On the following days all began to show flakes of 

 mycelium, or numerous multiplying cells of mycoderms, 

 tornlcB, and dematium ; and only four subsequently produced 

 yeast and alcoholic fermentation. From this we may con- 

 clude that, three months after the vintage, a large number of 

 the germs of yeast spread over the woody part of the bunches 

 lose their vitality, through desiccation by the surrounding air, 

 since two-thirds of the examples taken had become sterile 

 by that time. 



On January 21st we conducted a similar experiment with 

 twelve other tubes. A.t a temperature between 20° and 25° C. 

 (68° to 77° I'.) fermentation occurred in only two of them. 

 On March 2nd we undertook another experiment, again 

 using twelve tubes, and again fermentation occurred in two 

 tubes. 



By the beginning of April the sterility was absolute. At 

 that period of the year (April and May) we made numerous 

 experiments of this kind, using the woody parts of fresh 

 bunches of grapes and white grapes preserved from the last 

 Ajutage, plenty of which were still to be had in a state of 

 freshness at the provision store. We also operated on some 

 wood obtained from a vinej'ard at Meudon. In a great number 

 of cases no fermentation occurred ; it even happened that a 

 whole bunch of fresh black grapes, very ripe, which were bought 

 at Chevet's on April 16th, and which had been grown in a hot- 

 house, after having been crushed, did not ferment at all. 



