It must never be forgotten that the _elimination of uric acid_ displays wide _variations_, this even when the subject under investigation is on a _constant_ diet. Consequently, as Folin has pointed out, “even in the case of gout, which is distinctly associated with uric acid, it is an extremely difficult matter to prove by means of urine analyses that the uric acid elimination is not entirely normal.” And he adds, “If it had not been for the fact that uric acid, because of its insolubility, is so easily found in the joints, it would unquestionably have been a very long time before any definite relationship between uric acid and gout could have been established.” None can gainsay the truth of these reflections, for, when placed on a fixed diet, the uric acid output in the victims of _chronic gout_ differs but little from that of _normal_ individuals on a similar regime; save in this respect, that, following the intake of _purin-containing_ substances, the period of augmented uric acid excretion that ensues is _prolonged_ as compared with the normal. RETARDED EXOGENOUS URIC ACID OUTPUT In 1901 Vogt showed that in gout the excretion of exogenous purins was not only delayed but diminished. Giving simultaneously to a _gouty_ subject and a _healthy_ individual a diet rich in purins, he found that, in the former, _retention_ and _delayed excretion_ of _purins_ ensued. Vogt’s findings were confirmed by Reach, Soetbeer, Pollak, Mallory, and others. Brugsch and Schittenhelm also observed that, following the intake of purin-containing substances, the exogenous uric acid excretion was _retarded_ and _reduced_; in other words, the percentage of exogenous nitrogen excreted as uric acid nitrogen is less than in normal individuals, although the increased elimination extends over a longer period of time. On the other hand, Walker Hall finds that, though there is _retardation_, there is _no diminution_ in the output in gouty subjects. Thus he states: “When an adult takes a meal consisting of half a pound of beef and a quarter of a pound of sweetbread, containing about 0·620 gram purins, the moiety which usually occurs in the urine, say 0·300 gram, is not fully excreted until 6-10 hours have elapsed. When a similar meal is taken by a gouty individual the full 0·300 gram is eliminated, but the rate of output is delayed, some 48-72 hours being necessary.”