Now, owing to the fact that in _gout_ also considerable disintegration of the bone may result, the appearances in some instances may resemble those found in the skiagraphs of _rheumatoid_ joints. Stress has been laid on this similarity by Strangeways, and it was also previously remarked by Goldthwait. The latter, however, claims that while in _atrophic_ or _rheumatoid_ arthritis the bone, though thin, maintains its outline, on the other hand in _gout_ the outline of the bone is not distinguishable owing to its more complete destruction by the morbid process. Goldthwait holds that the resemblance of chronic articular gout to rheumatoid arthritis is most noticeable when the _articular ends_ of the bone in both instances are the seat of the disease. In other examples, however, the _shafts_ of the bones being affected by the gouty disorder, they may show punched-out areas. These latter, however, are but _focal areas of rarefaction_ seen in profile, and inasmuch as they may be met with in infective arthritides of non-gouty type, too much reliance cannot be placed on their presence as distinctive of gout, much less as a criterion of differentiation from other arthritides. We have to remember, too, that marginal proliferative changes may occur in rheumatoid arthritis. They are, like those met with in gout, miniature replicas of the bony outgrowths of osteoarthritis. In conclusion, the resemblance between the skiagrams of chronic gout and rheumatoid arthritis is so close as absolutely to forbid our sole reliance on skiagraphy to effect a differential diagnosis. In short, skiagraphy, though of great and probably increasing value, cannot for one moment be allowed to usurp the place of careful clinical observation, to which it must be held always subsidiary. Last, but not least, pending fresh radiographic revelations, our diagnosis of chronic articular gout and alike its differentiation from rheumatoid arthritis and other arthritides must rest on the one unimpugnable criterion, the presence of _tophi_. CHAPTER XXIV IRREGULAR GOUT “It is not a sacred disease. There will therefore be no profaneness in handling it freely,” affirmed Benjamin Rush of gout some hundred years since. Nevertheless one approaches with diffidence this debatable ground, so hedged in by high sanction and tradition. Albeit reverence for authority must, in the interests of progress, be tempered by that spirit of inquiring scepticism which would sift the chaff from the grain, this the more emphatically in that of all morbid conditions “irregular” gout, by the very vagueness of its clinical content, lends itself the more easily to unbridled inference, hazardous conjecture, and fanciful surmise.