=Chronic Rheumatic Arthritis= is very frequent in the hip, the shoulder, the knee, and the articulations of the hand. The process consists essentially, first, in an hypertrophy of the articular cartilage, generally at the margin, and principally near to the articular surface. Secondly, in the development of true osseous tissue in the hypertrophied cartilage. We will, therefore, find irregular enlargement of the articulating head of the bone; an absence of the articular cartilages, or new osseous growths surrounding their margins; and the synovial sacs presenting evidences of having been the seat of chronic inflammation. =Scrofulous Arthritis=, or _White Swelling_, attacks primarily the articular extremities of the bones. They become very vascular and softened, so that they can be readily cut with a knife, while a characteristic transparent and afterwards a yellow, cheesy substance is deposited in their cancelli. As the disease advances, the cartilage ulcerates, and the osseous tissue gradually wastes and undergoes a true caries. Abscess forms in the joint, and finds its way by ulceration to the external surface, causing numerous and circuitous sinuses in the neighboring soft parts. In some cases, the disease may commence in the synovial membrane, extending finally to the cartilages and ultimately to the bone. The disease affects principally the joints of children, and rarely occurs after the age of thirty. The existence of scrofulous disease in other parts, and the deposition of the yellow, cheesy matter within the cancelli, will serve to distinguish this disease from simple caries, resulting from inflammation. =Disease of the Spinal Column.= The joints of the vertebræ are liable to nearly the same affections as more perfectly developed articulations. The scrofulous disease just described may attack the cancellous tissue, causing caries and the deposition of cheesy matter. The first effects are generally perceptible where the intervertebral cartilage is connected with the bone, or in the intervertebral cartilage itself, although ulceration may commence on any part of the surface, or even in the centre of the bone. In some cases, of rarer occurrence, the bodies of the vertebræ are affected with chronic inflammation, with ulceration of the intervertebral cartilages as the consequence. If not checked, the disease proceeds to the destruction of the bodies of the vertebræ and of the intervertebral cartilages, leaving the posterior parts of the vertebræ unaffected. The necessary consequence is a curvature of the spine forward, and a projection of the spinous processes posteriorly.