Researches on the molecular asymmetry of natural organic products / by Louis Pasteur (1860).

  • Pasteur, Louis, 1822-1895.
Date:
1905
Catalogue details

Licence: Public Domain Mark

Credit: Researches on the molecular asymmetry of natural organic products / by Louis Pasteur (1860). Source: Wellcome Collection.

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    metry; and I could not point out the existence of any more profound distinction between the products formed under the influence of life, and all others. Let us enforce this point more strongly, for you will find the physiological side of these researches become more and more prominent in the remainder of this Lecture. Let us pass in review the principal classes of natural organic products. Cellulose, starches, gums, sugars,—tartaric, malic, quinic, tannic acids,—morphine, codeine, quinine, strych¬ nine, brucine,—essences of turpentine, of citron,—albu¬ men, fibrin, gelatin. All these immediate principles are molecularly asymmetric. All these substances in the state of solution possess the rotative power, a char¬ acteristic necessary and sufficient to establish their asymmetry, even when, crystallisation being impossible, hemihedry is lacking as a means of recognising this property. All the substances most essential in the animal or vegetable organism appear in this list. There are many natural substances which are not asymmetric. But are they natural in the same sense as the others? Must w^e not regard bodies like oxalic acid, hydride of salicyle, fumaric acid, etc., as derivatives of natural substances properly so called, formed by inter¬ actions analogous to those of the laboratory? These products appear to me to be, in the vegetable organism, what urea, uric acid, creatine, glycocoll, etc., are in the animal organism—execretions rather than secretions, if I may so speak. It would be very interesting to follow up this point of view experimentally. Let us add that many substances which are apparently not asymmetric, may be like paratartaric acid. We still want a word in chemica1 language to express the fact of a double molecular asymmetry concealed by the