another great problem opened up, for, as I said at starting, you have,
under ordinary circumstances in warm weather, merely to expose some
fluid containing a solution of sugar, or any form of syrup or vegetable
juice to the air, in order, after a comparatively short time, to see
all these phenomena of fermentation. Of course the first obvious
suggestion is, that the torula has been generated within the fluid. In
fact, it seems at first quite absurd to entertain any other conviction;
but that belief would most assuredly be an erroneous one.

Towards the beginning of this century, in the vigorous times of the old
French wars, there was a Monsieur Appert, who had his attention
directed to the preservation of things that ordinarily perish, such as
meats and vegetables, and in fact he laid the foundation of our modern
method of preserving meats; and he found that if he boiled any of these
substances and then tied them so as to exclude the air, that they would
be preserved for any time. He tried these experiments, particularly
with the must of wine and with the wort of beer; and he found that if
the wort of beer had been carefully boiled and was stopped in such a way
that the air could not get at it, it would never ferment. What was the
reason of this? That, again, became the subject of a long string of
experiments, with this ultimate result, that if you take precautions to
prevent any solid matters from getting into the must of wine or the wort
of beer, under these circumstances--that is to say, if the fluid has
been boiled and placed in a bottle, and if you stuff the neck of the
bottle full of cotton wool, which allows the air to go through and
stops anything of a solid character however fine, then you may let it
be for ten years and it will not ferment. But if you take that plug
out and give the air free access, then, sooner or later fermentation
will set up. And there is no doubt whatever that fermentation is
excited only by the presence of some torula or other, and that that