STUDIES ON FERMENTATION. 223 



pl3dng with these exigencies to the end. When the beer is 

 sold it is conveyed away, no matter what the season may be, 

 and deposited in the retailer's cellar, for a longer or shorter 

 time, according to the variations of consumption. On a warm 

 day beer will be in great demand ; the next day, if rain or cold 

 have come on, the demand will be very limited, since beer is, 

 in our climate at least, a drink for hot weather. From causes 

 of this nature, the beer may have to remain a long time in the 

 cellars of the retailers or consumers. By way of precaution, 

 indeed, it is put into very small casks, which permit of a 

 frequent renewal of the supply, and is conveyed to distances by 

 express trains, and during the night ; it is even sent away in 

 wagons provided with a kind of double case, the outer jacket 

 being filled with ice, which keeps the air surrounding the casks 

 constantly cold. Such are some of the troublesome measures 

 taken to obviate the danger that we have pointed out. They 

 operate very injuriously in restricting the trade and raising the 

 price of beer. It is a matter of extreme importance, then, that 

 our produce should be better removed from the action of those 

 microscopic enemies which beer contains ; in other words, that 

 this beverage should have less cause to fear circumstances 

 favourable to the development of the germs of impurity with 

 which it is always contaminated, as a natural consequence of 

 the methods of manufacture at present adopted. The question 

 of alteration in the flavour of beer should be regarded from 

 another point of view which merits equal attention. We have 

 seen that there are different kinds of beer, each of which corre- 

 sponds to a special ferment from which it derives its flavour 

 and aroma, and, in a word, everything which gives it a value 

 in the eyes of the consumer. It very often happens, especially 

 in badly-managed breweries, and more particularly in those in 

 which several beers are manufactured, that the yeast is a 

 mixture of difierent ferments. The evil efiects of such a 

 mixture are experienced in the course of manufacture, and 

 still more so in the beer after manufacture. Brewers in good 

 " low " fermentation breweries, who brew what is called stock 



