What, too, of all the other infective arthritides—_influenzal_, _pneumoccocal_, _scarlatinal_, _typhoidal_, _meningococcal_—to mention only those actually affiliated to some specific organism. For gout, be it noted, confers no exemption from other arthritic diseases, but how in time past were such to be differentiated therefrom? Again, gouty subjects, as has been recently emphasised, are notoriously prone to _pyorrhœa alveolaris_, and how difficult, given the supervention of an _arthritis_ in such to define the causal agent—_gout_ or _sepsis_, which? Small wonder then, that the clinical content of gout, not only to ancient, but also to latter day physicians, loomed large, swollen as it undoubtedly was by the inclusion of infective arthritides, not to mention those of _traumatic_ or _static_ origin. That more of these alien joint disorders—_les pseudo-rheumatismes infectieux_, as M. Bouchard terms them, were relegated to the “rheumatic” than to the “gouty” category, may perhaps be allowed, but still gout was undoubtedly allotted its full share and to boot. Moreover, if to “rheumatism” was wrongly affiliated the lion’s share of the _infective arthritides_, on the other hand to “gout” accrued a host of unrelated _visceral_ disorders, not to mention affections of the _nervous_ and _vascular_ structures, etc. In endeavouring to summarise the results of our brief retrospect, the somewhat chastening fact emerges, viz., that the isolation of articular gout has been achieved not so much by an increase in our knowledge as to what _is_ gout, but through our growing perception of what is _not_ gout. For of the _causa causans_ of gout we are still as ignorant as in the days of Sydenham. But, in contrast, our enlightenment as to the clinical and pathological features of other forms of arthritis has steadily progressed. In this way, shorn of many alien joint disorders, gouty arthritis has slowly but surely asserted itself as a specific joint affection, distinct both from rheumatism and arthritis deformans. In the course of our sketch, too, we have traced the evolution of the modern opinion that at least two separate conditions, “rheumatoid arthritis” and “osteoarthritis,” are comprised under arthritis deformans. This most tardily arrived at differentiation has done more than any other to clarify our conceptions as to what constitutes true “gouty arthritis.” If to this be added the further differentiation, not only of the _nerve arthropathies_, but also of the _infective arthridites_—both specific and undifferentiated forms—it will be seen that the term “gouty arthritis,” once the most comprehensive perhaps in all medical nomenclature, has now been brought within, at any rate, reasonable distance of more or less exact definition. CHAPTER III EARLIER THEORIES OF PATHOGENESIS