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.