The only morbid structural changes, therefore, that can legitimately be defined as _specific_ of gout relate to its _regular_ or _articular_ lesions. As to the _anatomical_ alterations in the articulations, their specificity depends essentially on the _uratic deposits_, rather than upon the associated inflammatory and degenerative processes. Given death during an _acute_ paroxysm, examination reveals the usual tokens of inflammation, hyperæmia, effusion, and swelling of the ligamentous tissues. The synovial lining is injected and spongy, while the exuded fluid is thick, scanty and turbid, containing polymorphonuclear leucocytes as well as _crystalline deposits_. Charged therewith, not only is the synovia thick, but of a milky appearance. Examined microscopically, it is found to contain the acicular crystals of _sodium biurate_. The synovia has occasionally been found covered with blood, but no _pus_ formation has ever been known to occur in uncomplicated acute gouty arthritis. The reaction of the synovial fluid is generally neutral or alkaline, but exceptionally Garrod found it acid. Uratic deposit has a predilection for _cartilage_, and in some instances is strictly confined thereto; but in the more _chronic_ forms it permeates all the component elements of the articulation. In the synovial membrane and fringes deposition takes place in the subepithelial and subserous layers. It invades also the ligaments, the tendons, and even the periarticular fibrous tissues become impregnated with biurate. Moreover, like the synovial sheaths of the tendons, the neighbouring bursæ are specially prone to deposits, which again encroaching upon the subcutaneous connective tissues, infiltrate the skin itself, forming chalk stones or tophi. Inspected after death, the articular cartilages are seemingly overlaid with a white mortar or chalk-like material, _i.e._, sodium biurate. Their surfaces, however, though defaced by stains, streaks, or dull patches, nevertheless, at any rate at first, retain their pristine smoothness. This because closer scrutiny reveals that the deposit is not in reality _upon_ the surface of the cartilage, but is located _interstitially_ in its substance. Microscopic examination of a vertical section, taken at the site of the deposit, shows clearly that it is composed of felted masses of acicular crystals. Lying in the matrix of the cartilage, they are more densely packed just below its free surface. The crystals do not penetrate further than one-third or one-half of the depth of the cartilage. Becoming more and more sparse towards the deeper layers, those near the bone are entirely free from deposit. This clearly indicates that the uratic matter originated from the synovial fluid bathing the articular ends and was precipitated therefrom.