more, of forming several crystalline combinations which
do not show any hemihedrism. It was the first exception
which Pasteur had encountered in this law of correlation
between hemihedrism and the rotary power. Now, ac-
cording to the current ideas of the epoch, fermentation
was a disintegration: it was the breaking up of a molecule
by decay, the débris of which, still voluminous, formed
new molecular edifices which were the products of the
fermentation. Consequently, by virtue of the theory
of Liebig, the edifice of amyl alcohol must form some
part of the framework in the molecule of the sugar in
order to resist dismemberment, and as it preserves the
rotary power its optical action must be derived from that
of sugar.

This idea was repugnant to Pasteur. He had seen,
for example, in malic and maleic acids, that the least
injury to the structure of the molecule made its rotary
power disappear. "Every time," he says, "that we
try to follow the rotary power of a body into its deriva-
tives we see it promptly disappear. The primitive
molecular group must be preserved intact, as it were,
in the derivative, in order that the latter may continue
to be active, a result which my researches permit me to
predict, since the optical property is entirely dependent
on a dissymmetrical arrangement of the elementary
atoms. But I find that the molecular group of amyl
alcohol is too far away from that of sugar, if derived from
it, for it to retain therefrom a dissymmetrical arrange-
ment of its atoms."

The origin of this alcohol must, therefore, be more
profound, and, recalling the before-mentioned fact that
life alone is capable of creating full-fledged new dissym-
metries, and thinking that his objection would no longer
have a raison d'être, if between the sugar and the amyl
alcohol a living organism were interposed, Pasteur

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