Of the causes of the disease but little is known, although it is generally attributed, like some other obscure affections, to the effect of rheumatism. It often follows in old people upon long disuse and confinement of a limb to one position, as during the cure of fractures. A very valuable specimen was presented to me lately by my friend Mr. Busk, of the Dreadnought hospital ship. The elbow had been apparently subjected to great injury. The radius and ulna had been fractured: the former had united, whilst a false joint had been formed betwixt the portions of the ulna. There is profuse deposit of bone around the elbow-joint, which must have been quite stiff, or nearly so, as regarded flexion and extension; but the end of the radius and corresponding articulation of the humerus are beautifully polished. This polish is not unfrequently seen also upon disunited fractures, as in the neck of the femur. Atrophy of the cartilages has been seen where no rheumatism was ever known to have troubled the patients; and they are more generally disposed to ascribe it to the effect of incessant hard work. At all events it is comparatively rare among women, and in the upper ranks of society; and the wasting often presents very much the appearance which would result from the effects of attrition, as if the wear of the cartilage had not been supplied by a corresponding reproduction. It is probable, therefore, that the affection is attributable to defective nutrition, somewhat allied to certain changes in the cornea, which are known to proceed from this cause, and which are also unattended by inflammation or the formation of pus. The symptoms of the disease are generally obvious enough in the more advanced stages by the crackling which may be heard when the joint is moved; and in the early stage a grating may be felt by a careful manipulation. SCROFULOUS DISEASE OF JOINTS.