Page:Popular Science Monthly Volume 11.djvu/343 HEAT AND MOTION,
AND POLITICAL ECONOMY. are correlated with the development of
microscopic organisms; this is fermentation proper. The other
set are dependent upon the action of amorphous soluble
substances; this is diastasic fermentation. Now, oxygen in a
state of tension arrests the former class of phenomena^ but in
the latter class it is without any action. Thus we can entirely
prevent the fermentation of must, the souring of wine, the
putrefaction of meat, etc., by means of oxygen in the state of
tension. This work once done, we may restore the normal
pressure, and then, provided germs from without are excluded, no
true fermentation will occur. I once hoped to be able in this
way to preserve meats, eggs, etc., but this was an illusion. The
substances do not become putrid, but, in consequence of a
pseudo-fermentation, which sours them, they acquire a
disagreeable taste, which takes from the process all its
industrial value. At the close of this long discourse