In this connection we may note that McClure has recently emphasised the fact that the _kidneys_, in the _later_ stages of gout, are often _functionally_ deficient, and that, accordingly, the faulty elimination of exogenous uric acid by gouty persons may be simply the result of such _functional renal depression_; in other words, not due to gout, but to the _secondary_ or _associated renal deficiency_. Hence, having regard to the frequency with which renal inefficiency is met with in gout of any standing, he is inclined to discount the value of studies of _exogenous uric acid elimination_ as an aid to the diagnosis of gout. Consequently, he holds that before the diagnostic status of retarded purin elimination, as a symptom of gout, can be established, an investigation of the output of uric acid in the different types of _nephritis_ is essential. From the foregoing it will be seen that we stand in urgent need of further studies of _early_ or _oncoming_ gout and of _early nephritis_ before we can with certitude impeach the _kidneys_ as responsible for the delay in exogenous purin output. Meanwhile, too, we must be careful not to overlook the further disconcerting fact, previously adverted to, that the retardation and diminution of exogenous purin output is not _invariable_ in gout. Nor, for that matter, is it _peculiar_ to gout, considerations both of which, if confirmed, will still further discount the _diagnostic_ significance of this phenomenon. URICÆMIA IN NEPHRITIS Von Jaksch and Klemperer noted long since that in chronic interstitial nephritis urates are always present in the _blood_. Now, according to Folin and Denis, human blood contains 1·5-2·5 mg. of uric acid per 100 c.c.; but if the eliminating powers of the _kidney_ be deficient, the uric acid content thereof rises, sometimes to as high as from 15-20 mg. per 100 c.c. But more interesting still the fact noted by Fine, viz., that even in _early_ interstitial nephritis the same feature is well marked, _i.e._, the blood may contain 4-8 mg. of uric acid per 100 c.c. Indeed, according to this authority, increase in the _uric acid_ content of the blood is the first signal of impaired renal efficiency. This, be it noted, without any coincident proportional increase in the blood content of _urea_ or _creatinine_. The sequence would appear to indicate that the damaged organ encounters greater difficulty in excreting _uric acid_ than these other metabolites. But, _pari passu_ with the advance of the renal disease, retention of _urea_ is superadded, and still later _creatinine_. So constant, indeed, the sequence that, by determining the percentage amount of these three _metabolites in the blood_, the measure of the renal mischief may be gauged.