274 FKAGMENTS OF SCIENCE. 



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 

 organisms, have their activity suspended by tempera- 

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

 torpor the beer remains untainted either by acidity or 

 putrefaction. 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 

 forcing its consumption to avoid the loss involved in 

 its alteration if kept too long. Hops, it may be 

 remarked, act to some extent as an antiseptic to beer. 

 The essential oil of the hop is bactericidal : hence the 



