THE ASYMMETRY OF THE CYCLE OF LIFE 149
organism
is without action on the dextro-tartrate; the Penicillium leaves the
laevo-tartrate untouched. This, as Pasteur demonstrated, is one method of
separating the two in a mixture. Now, it is a remarkable fact that when any of
these isomeric compounds are manufactured in the laboratory, equal amounts of
the dextro- and of the laevo- compounds make their appearance in the mixture.
Pasteur first noted the fact that all the artificial products of the
laboratories and all the sorts of minerals encountered in nature are without
action on polarized light, unlike all the naturally occurring organic
compounds. This has only altered since 1860, according to Duclaux, in that,
while chemists can manufacture certain of these compounds in mixtures of equal
amounts of the isomers, they can also be separated by the action of ferments,
which are specific in this direction. For other alterations see the works of
Pope and van ‘t Hoff.* In the two lectures Pasteur demonstrated that the
naturally occurring organic compounds rotate the plane of polarized light to
the right or to the left, and in this way are dextro- or laevo-rotatory. As
Duclaux writes, “Nature alone knows how to manufacture the one isomer without
producing the other.” “A living cell is a laboratory of dissymmetrical forces,
or a dissymmetrical protoplasm, acting under the influence of the sun.”
In
his “Chemical Statics and Dynamics,” Dr. J. W. Mellor** writes as follows: “ It
is interesting to observe that only the dextro-sugars occur in Nature (?), and
that these are the only sugars which can be assimilated as foodstuffs by the
yeast-plant. No organism capable of
* van ‘t Hoff,
J. H.:” Stereo-Chemie nach van ‘t Hoff’s Dix Annees dana 1’Histoire d’une
Theorie, neu bearbeitet von W. Meyerhoffer,” 1892.
** Molar, J. W. “Chemical Statics and
Dynamics,” London, 1904.