340 



STUDIES ON FERMENTATION. 



experiment might have been protracted over any number of 

 years with the same result. 



The only change that occurs in course of time is the appear- 

 ance in the neck of the flask at the surface of the beer of a 

 deposit of small prominences resembling a crystallization, but 

 which really consists of those forms of ferment to which in 

 Chapter Y. I attached the name of aerobian ferment. The beer, 

 after being transferred to a bottle that had been washed with 

 not water, was kept for several months in the heat of summer, 

 without exhibiting the slightest trace of deterioration. 



The essential conditions of the preceding experiment can 



Fig. 



Fig. 



readily be realized on the large scale. For this purpose we may 

 employ the apparatus in the above sketch (Figs. 76 and 77) 

 constructed of tin or tinned copper. As appears from the 

 sketch, this consists of a cylindrical tub resting on a support, 

 and closed at the top by a cover, whose lower edge fits into a 

 gutter containing water. The wort prepared in the copper is led 

 into the cylinder, a process which does not materially lower its 

 temperature. Now we know that wort in breweries which has 



