2.—In the next class of cases, in which stiffness is due to degenerative changes, the external appearances are exactly reversed, the outlines of the joint are more or less gone. In these cases, no matter the character of the disease, manipulative interference is positively vicious; and while it is in them that ignorant Bone-setters do so much mischief, the better informed, by the use of splints and well applied pressure, are highly successful in their treatment. I am sorry to say many cases of this kind come to Bone-setters which have not been properly treated before, owing to their not having been recognised, especially hip-joint disease. 3.—On the third-class of cases, in which a fracture has taken place into the joint, causing stiffness, the condition is due to disturbed relationship of the bones from faulty setting, and is recognised by comparison with the bony landmarks of the sound limb. In these cases forcible treatment does good; though, of course, the result is in proportion to the amount of bone-displacement, but it should be supplemented by passive movements for some time. In joints stiff after diagonal fracture through the condyles of the humerus so common in children, I have seen many most gratifying results; one in a boy about twelve years old, whose elbow had been stiff three years is especially impressed on my mind. 4.—In the fourth-class of cases, and those to which I would draw particular attention, I include lameness, and weakness, the result of the various forms of injury, which we group together under the general term a “sprain.” I affirm most unhesitatingly, from an experience of some hundreds of cases, that nothing has done more to lower the prestige of regular practitioners, and to play into the hands of unqualified Bone-setters, than the way in which so many practitioners tamper with a sprained joint. Sprains, of course, vary greatly in severity; they may be broadly divided into two kinds, of which one consists merely of a temporary over distention of the parts round a joint which rest, and anodyne applications soon cure, while the other involves pathological results a much more serious nature. A _severe_ sprain is the sum of the injuries that the parts in and about a joint sustain, when, by their passive efforts, they exercise their maximum power of restraint to prevent luxation. Under such conditions I conceive the following changes to take place in the integrity of a joint. In the case of the synovial membrane, temporary hyperæmia accompanied by pain, and some slight effusion into the cavity of the joint.