272 FRAGMENTS OF SCIENCE. 



partly because the yeast of the beer, instead of rising 

 to the top and issuing through the bunghole, falls 

 to the bottom of the cask; but partly, also, because it 

 is produced at a low temperature. The other and 

 older process, called high fermentation, is far more 

 handy, expeditious, and cheap. In high fermentation 

 eight days suffice for the production of the beer; in low 

 fermentation, ten, fifteen, even twenty days are found 

 necessary. Vast quantities of ice, moreover, are con- 

 sumed in the process of low fermentation. In the 

 single brewery of Dreher, of Vienna, a hundred million 

 pounds of ice are consumed annually in cooling the 

 wort and beer. Notwithstanding these obvious and 

 weighty drawbacks, the low fermentation is rapidly dis- 

 placing the high upon the Continent. Here are some 

 statistics which show the number of breweries of both 

 kinds existing in Bohemia in 1863, 1865, and 1870: 



I860. 1865. 1870. 



High Fermentation . . 281 81 18 

 Low Fermentation . . 135 459 831 



Thus in ten years the number of high-fermentation 

 breweries fell from 281 to 18, while the number of low- 

 fermentation breweries rose from 135 to 831. The 

 sole reason for this vast change a change which 

 involves a great expenditure of time, labour, and money 

 is the additional command which it gives the brewer 

 over the fortuitous ferments of disease. These fer- 

 ments, which, it is to be remembered, are living organ- 

 isms, have their activity suspended by temperatures 

 below 10 C., and as long as they are reduced to torpor 

 the beer remains untainted either by acidity or putre- 

 faction. The beer of low fermentation is brewed in 

 winter, and kept in cool cellars; the brewer being thus 

 enabled to dispose of it at his leisure, instead of for- 



