Under the vague term “articulorum passio” or “arthritis” the physicians of antiquity handed down to posterity the clinical description of a disease in the varied symptomatology of which we may descry at one time the features of gout and anon those of rheumatism. But centuries had to elapse before gout became differentiated from rheumatism. For there is no doubt that not only the Greek and Roman physicians, but those also of the Græco-Arabian school, confounded these two disorders, or more accurately failed to differentiate rheumatism. So it is that Charcot, reviewing the antiquity of gout, while he pays a graceful tribute to the ancient physicians for their masterly disquisitions thereon, at the same time deplored their silence on the subject of articular rheumatism. This absence of allusion thereto is the more remarkable in that the term “rheumatism” or “rheumes” dates from a very remote period. Both words, in truth, were indifferently enlisted to denote all those diseases deemed attributable to the defluxion of some acrid humour upon one or other part of the body. Used by the ancients more in accordance with its etymological sense, the term “rheumes” or “rheumatism,” finds a place even in the writings of Pliny and Ovid. But our modern conception of the disorder differs widely from “the flux of humours” which the Greeks named rheumatism, or “the sharpe and eager flux of fleam” which for them characterised an attack of the “rheumes.” The early English authors, too, invoked the word as a general term descriptive of various forms of disease. Sir Thomas Elyot, in his “Castel of Health,” so scoffed at by the faculty in his day, inculcates abstemiousness in those afflicted with the “rheumes,” and in “Julius Caesar,” Brutus is warned by Portia not to tempt “the rheumy unpurged ayre of night,” a clear indication that the term was used as a synonym for fluxions, humours and catarrhs of all sorts. But as to the malign _articular_ forms of the affection, never a word; and this almost inexplicable silence led Sydenham, Haecker and Leupoldt to surmise that articular rheumatism was a modern disease unknown amongst the ancients. ISOLATION OF ACUTE ARTICULAR RHEUMATISM FROM GOUT Hallowed by tradition, this erroneous conception of the identity of gout and rheumatism endured until 1642, when Baillon, in his treatise “De Rheumatismo et Pleuritide,” effected a cleavage, at any rate between the acute varieties of these two diseases. Dissociating the term “rheumatism” from its primitive interpretation, Baillon restricted its usage to that particular group of symptoms we now call _acute articular rheumatism_. In the same century Sydenham, in his “Classical Observations,” materially clarified the existing clinical confusion, defining with his customary lucidity the essential differences between the two disorders. TARDY DISSOCIATION OF CHRONIC GOUT FROM CHRONIC RHEUMATISM