When the disease begins with swelling, which is of a chronic character, and produces but little inconvenience, and when the more urgent symptoms supervene after the swelling has continued for a considerable time, there is every reason to suppose that the disease has originated in the synovial membrane, or perhaps in the osseous cancelli, and this is generally met with in poorly fed and strumous subjects. But when the first symptoms have been pain and stiffness of the joint, without change of its appearance, and when the swelling has occurred after these symptoms have been of some duration, then it is probable that the cartilages are the primary seat of mischief. For the most part, however, the symptoms have a general resemblance in most chronic affections of the joints, and all the apparatus is sooner or later involved. When the cartilage has been extensively absorbed, a grating sensation is felt in moving the articular surfaces of the bones upon each other. In consequence, also, of the softening and disorganisation of the lateral and other ligaments, the affected articulation at length becomes unnaturally loose, which is owing in some measure, also, to the muscles being wasted and paralysed from pain and disuse. At an earlier stage of the disease, the joint may be rigid from deposition of lymph into the contiguous cellular tissue, and contraction of the muscles. Purulent matter not unfrequently collects in the substance of the bones, which in all cases ultimately become softened in a remarkable manner. In many subjects, without actual disease of the osseous tissue, the heads of the bones are so altered in consistence, are so deficient of earthy matter, as to be easily cut with a knife. It has been a matter of dispute, whether, in this affection, the articulating extremities of the bones are enlarged or not; and the supposition that they are always more or less increased in size, or hypertrophied, has arisen from the extensive effusion and indurated state of the soft parts being mistaken for this enlargement. In the first stages of the disease, they are seldom, if ever, enlarged; but when ulceration of the bone has occurred, new osseous matter is deposited to a greater or less degree in the neighbourhood of the ulcer,—an attempt by nature towards a cure, but too often an ineffectual one. The bones, in strumous subjects, are often much enlarged, from collection of purulent matter in their substance giving rise to a sort of spina ventosa. I removed the upper extremity of a boy lately on account of extensive disease about the elbow. The ulna to near the wrist was swollen enormously by purulent collections in its medullary canal. In cases when the whole of the articulating extremity of the bone is not enlarged, still that portion which is more immediately concerned in the articulation is often considerably expanded.