STUDIES ON FERMENTATION. 125 



of purity, by means of a piece of platinum wire, in the manner 

 already explained in connection with propagation of other 

 fungoid growths On December 19th a young and thin film of 

 mycoclenna aceti covered the surface of the liquid. AVe then 

 poured out the liquid through the right-hand tube, at the same 

 time heating the end of the bent tube, to purify the air that 

 passed into the flask. The whole film of mycoderma aceti re- 

 mained adhering to the interior sides of the flask during this 

 decanting. The question then was how to conve}^' this film of 

 the little plant into a saccharine liquid of a particular kind. 

 We effected this easily by the following means : After having 

 emjDtied the flask, as just described, instead of re-closing the 

 india-rubber nozzle on the end of the right-hand tube, we 

 attached it to a test-flask containing the saccharine liquid on 

 which we wished to operate. This had been previously boiled 

 in the test-flask, and when we attached the neck of the 

 test-flask, previously slightly drawn out and curved, to the 

 india-rubber tube, the liquid was still very warm. We per- 

 mitted the liquid in the test-flask to cool down, and, then, 

 taking up the test-flask, we decanted its contents into the other 

 flask, in which, as we have already said, the film of mycodenna 

 aceti had been left. In this way the film became partly sub- 

 merged, partly spread over the surface of the new liquid. Ex- 

 periments were made with two saccharine liquids, must and wort. 

 In the case of the latter, from December 22nd the whole surface 

 of the liquid was covered by a film of mycoderma aceti, which 

 even spread up the moist sides of the flask above the level of the 

 liquid. In the case of the must, on the other hand, the plant 

 for some time did not seem to be developing ; on December 24th, 

 however, it was visibly spreading over the surface of the must. 

 The following days we frequently shook up the films to separate 

 them, and spread them over the subjacent liquid. There were 

 no signs of alcoholic fermentation. 



On December 30th we introduced several grammes (50 or 60 

 grains) of carbonate of lime into each of the flasks, an opera- 

 tion of little difficultv, which we effected in a manner similar to 



