This disease occurs most frequently about the middle period of life, but is, however, very often seen in children. It will never appear before the age of puberty without a deviation from health, but not always so when it makes its appearance in after-life. It is a disease of the knee-joint characterized by swelling and white color, owing to the tension of the skin. It is of two varieties; both, however, destroy the synovial or articular membrane of the joint. One begins with a trifling stiffness, slight swelling, and in effect reduces the membrane to a pulpy, degenerate mass. The swelling increases gradually, and when the part is touched, it reveals the presence of fluid. Finally the cartilages ulcerate, and the disease assumes such characters that amputation becomes absolutely necessary. The other form begins with pain in the joint, which is severe at one point, and attains its height in a week. It is characterized by inflammation of the synovial membrane, and in a few days the joint becomes swollen from a collection of water.

TREATMENT. -- At the commencement bathe the parts with the following liniment:--oil of hemlock, 3 iv.; dissolve as much camphor in it as it will take up, and add twelve drops of croton oil, and three drachms of tincture of iodine. Bathe the limb thoroughly, after which apply hot cloths wrung from a strong infusion of arnica flowers and lobelia, and change as often as they grow cool; with each change apply the liniment. This will arrest the disease if applied at the onset. The patient should be purged, and the compound syrup of chimaphila be administered to him. If the disease is farther advanced, and openings exist, they should be enlarged, and ointments and poultices applied, and the constitution supported by tonics and antiseptics. Splints and entire rest may be necessary in some cases, and when connected with a scrofulous diathesis, my "Blood Purifier" should be taken internally, and the "Herbal Ointment" applied externally. These will quickly eradicate the disease.