The physiology of the carbohydrates : a reply to Dr Pavy's "Epicriticism" / by D. Noël Paton.

  • Paton, Diarmid Noël, 1859-1928.
Date:
1896
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Licence: Public Domain Mark

Credit: The physiology of the carbohydrates : a reply to Dr Pavy's "Epicriticism" / by D. Noël Paton. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    the value of his work and the validity of his conclusions depend so greatly upon these methods, they require careful considera- tion. 1. My objection to the alcoholic method of extracting sugar on the ground that varying proportions of maltose and of the lower dextrins may be taken up will not, I think, be considered a “ gratuitous innuendo ” by those who know about the relative solubility of the carbohydrates in different strengths of alcohol. Dr Pavy uses alcohol (absolute?) or methylated spirit,—a weaker spirit,—and he puts into this the water containing blood or tissue in the proportion of 30 to 400, and thus dilutes his alcohol still further. In such a spirit, even if over 90 per cent, of alcohol, the sugars and dextrins will be taken up in varying pro- portions. It is not as if there was a hard and fast line between carbohydrates soluble in, and carbohydrates insoluble in such alcohol, but a continuous chain of intermediate bodies exists, and the amount of these taken up or left will depend upon the amount of dilution of the alcohol. In his “ Epicriticism ” Dr Pavy admits this difficulty, but he does not seem to appreciate fully the modifications in his results which it may introduce. 2. In regard to Dr Pavy having shown, by “subsequent aqueous extraction ” (p. 38), that all the glucose had been removed by his alcoholic extraction of blood and tissue, the results of Scheuck must be borne in mind. To the work of this observer I have already called Dr Pavy’s attention, but he still continues to ignore it entirely. Coming as it does from Professor Pfluger’s laboratory in Bonn, it must be received with respect, and cannot simply be ignored as Dr Pavy tries to ignore the admirable work of Panormoff, the “ Privat-Docent of the University of Kazan ” (p. 128). It has a most important bearing on all Dr Pavy’s work, and is worthy of his careful study and consideration. By adding weighed quantities of pure glucose to defibrinated blood, to serum, and to each of the two proteids of the serum, Schenck found—I quote his words—“ that after coagulation only a part is to be found in the filtrate. If the coagulum has been washed with water or alcohol until the watery or alcoholic extract contains no more trace of a reducing substance, and the coagulum is then boiled with dilute hydrochloric acid, reducing substances may be recovered in the fluid, which, in successful cases, correspond to the amount of sugar lost. It is highly probable from this that the glucose is combined with the albumins of the blood.” In the course of his paper he indicates the difficulty introduced by the sugar naturally present. It must be remembered, too, that the deficits of sugar are not trifling, but amount to as much as 46 and 47 per cent, of the amount added, and the difficulty in the extraction of added glucose will also be experienced in extracting that normally