Gout : its pathology and treatment / by Arthur P. Luff.

  • Arthur P. Luff
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Gout : its pathology and treatment / by Arthur P. Luff. Source: Wellcome Collection.

    79/272 page 67
    Renal Excretion. 6/ another class produce urea. Thus, in the urine of the carnivorous lion and tiger there is a quantity of urea and but very little uric acid ; on the other hand, the carnivorous python and boa excrete uric acid and no urea. Graminivorous birds excrete uric acid and no urea, whilst herbivorous mammals ex- crete quantities ol urea and but little or no uric acid. Sir William Roberts,* comparing the functions of the kidneys of birds and serpents with those of mammals, considers that an immense functional evolution has taken place in the mammalian kidney ; that the evolution of mammalian urine has probably turned mainly on the point that the mammalian plan required that the renal excretion should be voided not in the solid or semi-solid form, but as a watery solution. This modification would require the discarding of the sparingly soluble uric acid as a medium for the elimination of nitrogen, and the substitution of a nitrogenous substance readily soluble in water, such as urea. He considers it possible that the reason why this substitution has not been completely effected is that in that particular the mammalian type has not yet reached its ideal perfection, and that the residuum of uric acid in mammalian urine may be something in the nature of a vestigial feature. VIEW THAT URIC ACID IS FORMED FROM UREA IN THE KIDNEYS. In mammalia, including man, and in birds uric acid is absent from the blood in health, * Croonian Lectures on Uric Acid Gravel and Gout, 1892, p. 33.
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