ased 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 somewhat elongated. The other
organisms are more or less rod-like or eel-like in shape, some of them
being beaded so as to resemble necklaces. Each of these organisms
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 unconsciously, 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 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 consumed 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
displacing the high upon the Continent. Here are some statistics
which show the number of brewerie