THE BACTERIA IN DIFFERENT MEDIA. 14] 
liquid in which this mycoderma is cultivated should 
be a little acid, containing one-half per cent of 
acetic acid, for example. Under these conditions 
the Mycoderma vini (a species of Saccharomycete), 
the formation of which should be avoided, finds 
conditions unfavorable to its existence. Indeed, 
this second organism, commonly called flowers of 
wine, has an action quite different from that of 
the Mycoderma aceti. It consumes the alcohol 
entirely, transforming it into water and carbonic 
acid: it also consumes the acetic acid. We must 
sow the JZ. aceti, if we do not wish to see the MW. 
vini develop in its place, as the germs of the latter 
seem more widely diffused in the air. 
In order that the acetification may occur, the 
oxygen of the air is necessary. Once submerged, 
the MM. aceti develops, but no longer produces 
acetic acid. It is even probable that it consumes 
the acetic acid already formed, reducing it to the 
state of water and carbonic acid. It is the same 
when, developing upon the surface, it has trans- 
formed all the alcohol. “In effect, it is not then 
arrested in its work; and without changing form 
or mode of action, it carries the oxygen of the air 
to the acetic acid which it has produced, transform- 
ing it into carbonic acid and water. If we add some 
alcohol to the liquid, the phenomena change: the 
acid is respected, and the alcohol is transformed 
anew into acetic acid” (Duclaux). According to 
the experiments of Mayer, the maximum of aceti- 
fying power is obtained between 20° and 30° (68° 
to 86° Fah.), and this power is lost below 10° (50° 
Fah.) and above 35° (95° Fah.). 
