According to Tilden Brown, the rhythm of urea excretion constitutes a warning as to the approach of gout. A very lowered elimination thereof he holds to be an excellent and pathognomonic symptom. The excretion of urea may at times run so low as to lead to a suspicion of _renal_ disease. He considers that this sign may find a place in the prophylaxis of gout, a signal for the initiation of treatment with the object of lessening the severity of symptoms (viz., extent of toxic action as manifested by destruction of proteid, etc.). This point was advanced by Brown (1905) during a discussion at the Harvard Medical Society, but as far as we know it has not been confirmed. Presumably it rested upon the assumed existence of a normal ratio of uric acid elimination to that of urea with the corollary that every deviation therefrom was due to a pathological cause. Haig held this view, which was, however, disproved by Herringham, Groves and Luff. The latter authority estimated the daily eliminations of uric acid and urea in a healthy adult man on a mixed diet for a period of fifty days, and clearly showed that no constant ratio exists in a given individual between the excretion of uric acid and urea. Also, it is obvious that, before attaching any valency to Tilden Brown’s dictum, it is essential that it be established that the cases were instances of pure gout, unaccompanied by _nephritis_. Moreover, modern workers tend more and more to rely not on analyses of the urine but of the _blood_, especially in the unravelling of so-called metabolic disorders. Also, it may be added, that their findings in this sphere indicate no harmony between the urea and the uric acid content of the blood. Thus, Otto Folin observes, “One most interesting fact which we constantly meet with in blood analysis is that there is no correspondence between uric acid and the total non-protein nitrogen in the blood. In gout or lead poisoning, or leukæmia, the blood is uniformly rich in uric acid, yet the total non-protein nitrogen or _urea_ nitrogen may be normal.” CREATINE AND CREATININE As before pointed out, it has been suggested that these substances may be in some obscure way related to the genesis of _gout_. To this end a great amount of research has been expended on the metabolism of creatine and creatinine. But although, as far as I am aware, the revelations hitherto forthcoming have disclosed no link between these substances and the development of gout, still, by reason of the potentialities possibly resident therein, a brief digression is permissible. The exact origin of creatine and creatinine is still obscure. All we know is that they are, in the main, the outcome of chemical processes in the tissues, viz., products of _endogenous_ metabolism. Also of the creatine and creatinine present in food a moiety may appear as creatine in the urine.