As to whether in healthy individuals, on a purin-free diet, similar variations in the uric acid content of the blood occur, is not sufficiently ascertained. The solitary example that may be cited is by McLester, who, as a result of four examinations of the blood in a normal person on a purin-free diet, found that its uric acid content was practically constant. The deductions that may be drawn from the foregoing findings are:— (1) That in _gouty_ subjects pronounced variations of the uric acid content of the blood may occur which are not attributable to the purin content of the food. (2) That in _non-gouty_ arthritis similar fluctuations in the blood content of uric acid, irrespective of diet, also occur. (3) That in _normal_ persons, on a purin-free diet, the blood content of uric acid, as far as is ascertained, does not show such variations. WHAT RELATION, IF ANY, EXISTS BETWEEN THE URIC ACID CONTENT OF THE BLOOD AND ATTACKS OF GOUT? If uric acid be _causally_ related to gout, it would seem reasonable to expect that the blood content thereof would stand in some clear relation to the _incidence_ or _intensity_ of attacks. But, according to Pratt and others, no variations indicative of such a relationship obtain. For, independently of _acute_ attacks, and, moreover, in the absence of any pronounced _renal inadequacy_, the blood of gouty subjects, even on a _purin-free_ diet, contains, as a rule, 4-9 mg. of uric acid. More pertinently to our point, in the experience of Daniels and McCrudden, it transpires that, contrary to the usually accepted teaching, typical _acute_ attacks might occur without any variation in the _uric acid content of the blood_ or its _excretion_. Nor did their iconoclastic findings cease here, for, _mirabile dictu_! attacks ensued even when the uric acid blood content was at a _sub-normal_ level; this latter, owing to the victims being at the time on _atophan_, which increases uric acid elimination. In this connection it is worthy of note that, according to Pratt, the uric acid content of the blood may at times be low, even when atophan has not been taken. In one of his cases, on a purin-free diet, only 1·7 mg. was present, and in another case, on a mixed diet, 1·9 mg. Daniels and McCrudden, too, note that the uric acid content of the blood in gouty subjects may be _persistently_ lowered, _even under the normal average_. His, again, has recorded an instance of a gouty subject, with multiple tophi, whose blood did not contain an excess of uric acid. Bloch, also, took 200 c.c. of blood from a man, aged twenty-five, suffering at the time from a typical attack of gout in the big toe; but uricæmia was not present.