The chemical synthesis of vital products and the interrelations between organic compounds : Vol. 1 / by Raphael Meldola.

  • Meldola Raphael, 1849-1915.
Date:
1904
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Licence: In copyright

Credit: The chemical synthesis of vital products and the interrelations between organic compounds : Vol. 1 / by Raphael Meldola. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    that orcinol or a derivative would have to be as it were built into the structure of the molecule. This phenol, which has of course been completely synthesised, has therefore been included among the vital products, and it is not at all improbable—in view of the facility with which some of the lichen acids furnish the compound by chemical treatment and even by bacterial action—that it may yet be found in the vegetable kingdom. Resorcinol [vo] presents a similar case, only the evidence that the complex is contained in vital products such as paeonol [133], euxan- thone [136], &c., has been in the first place obtained by the more violent method of fusing with alkali. It is hardly likely that this phenol will be ever found in the free state in plants, but it must nevertheless be regarded as a vital product, since it has been proved by synthesis as well as by the action of heated alkali that resorcinol is one of the generators of both paeonol and euxanthone. For similar reasons the pyrogallol [84] complex is regarded as being present in gallic acid, &c., the phloroglucinol [86] complex in many colouring-matters of the pyrone group, and so forth. Another instructive example is furnished by hydro]uglone [90] from the walnut, Juglans regia. This compound is known to be a derivative of naphthalene, and as it contains the naphthalene complex the syntheses of this hydrocarbon are given in connexion with the phenol. While these pages were undergoing final revision it was announced by V. Soden and Rojahn (Pharm. Zeit. 47, 779) that the hydrocarbon itself had been found in certain vegetable ethereal oils. III. ORGANIC CHEMISTRY FROM THE BIOCENTRIC STANDPOINT The general tendency of the present work is to bring Carbon Chemistry back to the point from which it departed three-quarters of a century ago, when the leading discovery of the synthesis of urea by Wohler showed that organic compounds could be formed without vital intervention. Without desiring to reopen the question of the existence of a special ‘ vital force,’ it may be well to call the attention of those physiologists who appeal to the achievements of synthetical chemistry as conclusive evidence against the existence of such a force to the fact—so distinctly brought out by the summary of experimental results herein recorded—that the testimony of pure chemistry cannot, as it at present stands, be legitimately interpreted into a direct nega- tion of Vitalism in any form. This negation may, and probably will, be made possible in the future when our chemical methods have been made to approximate more closely to the vital methods. In the meantime it must not be forgotten that there is at present but little reason for believing that our laboratory methods have much analogy with the processes which go on in the living organism. All
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