FERMENTATION. 271 



guides lost in the crevasses of Alpine glaciers have 

 come to the surface forty years after their interment, 

 without the flesh showing any sign of putrefaction. 

 But the most astonishing case of this kind is that of 

 the hairy elephant of Siberia which was found incased 

 in ice. It had been buried for ages, but when laid 

 bare its flesh was sweet, and for some time afforded 

 copious nutriment to the wild beasts which fed upon it. 



Beer is assailable by all the organisms here referred 

 to, some of which produce acetic, some lactic, and some 

 butyric acid, while yeast is open to attack from the 

 bacteria of putrefaction. In relation to the particular 

 beverage the brewer wishes to produce, these foreign 

 ferments have been properly called ferments of disease. 

 The cells of the true leaven are globules, usually some- 

 what elongated. The other organisms are more or less 

 rod-like or eel-like in shape, some of them being bead- 

 ed so as to resemble necklaces. Each of these organ- 

 isms produces a fermentation and a flavour peculiar to 

 itself. Keep them out of your beer and it remains for 

 ever unaltered. Never without them will your beer 

 contract disease. But their germs are in the air, in 

 the vessels employed in the brewery; even in the yeast 

 used to impregnate the wort. Consciously or uncon- 

 sciously, the art of the brewer is directed against them. 

 His aim is to paralyze, if he cannot annihilate them. 



For beer, moreover, the question of temperature is 

 one of supreme importance; indeed, the recognised 

 influence of temperature is causing on the continent 

 of Europe a complete revolution in the manufacture of 

 beer. When I was a student in Berlin, in 1851, there 

 were certain places specially devoted to the sale of 

 Bavarian beer, which was then making its way into 

 public favour. This beer is prepared by what is called 

 the process of low fermentation; the name being given 



