Physiology of the carbohydrates : an epicriticism / by F. W. Pavy.

Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: Physiology of the carbohydrates : an epicriticism / by F. W. Pavy. 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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    ting may yield a carbohydrate. But we have to consider the question of whether the evidence offered proves that such a carbohydrate molecule is yielded. Now, the caz'bohydrates are not the only bodies which yield crystalline compounds with phenyl- hydrazin. A glance at Beilstein’s Organic Che- mistry shows that a vast number of substances give such crystalline compounds. It is only when an elementary analysis of the compound is made that it can be definitely concluded that a carbohydrate is a constituent part. Such analyses are given by Baisch in his researches on the carbohydrates of the urine, and bv Bial in his observations on the sugar produced by the ferment of the blood, and the conclusions of these authors are thus placed beyond doubt. But Dr. Pavy does not give such analyses, and without them we are not justified in accepting his conclusion that the substance is a carbohydrate.” Reference need not be specially made to Beilstein’s ‘ Organic Chemistry ’ to learn that there are other substances besides the cupric oxide reducing sugars which give crystalline osazones with phenyl-hydrazin. It is now stock knowledge what kind of bodies do so, and that they are restricted to certain groups pos- sessing a particular molecular constitution. It may be said that neither of them besides the carbohydrate could live under the treatment to which my cleavage product is exposed,—namely, first of all boiling with 10 per cent, potash solution, and then with 10 per cent, sulphuric acid before being brought under the influence of the phenyl-hydrazin. This is