Sir B. Brodie, who has done a great service to the profession by directing attention to these nervous affections in his excellent work, and in his lectures, notices that the knee, when the seat of pain, is generally kept in the extended position, and this is very different from what has been stated to be the position of one affected by organic disease. The tumefaction following upon local treatment, and especially when leeching and counter-irritants have been employed, is sometimes, as he remarks, very perplexing. This class of diseases generally affects females of delicate organisation about the age of puberty, and in whom the menstruation is irregular. Males in delicate health are also subject to similar affections. ON GROWTHS FROM THE SYNOVIAL MEMBRANE, AND LOOSE SUBSTANCES IN THE JOINTS. The synovial membrane is sometimes studded on its inner aspect with loose fleshy or semicartilaginous substances projecting into the cavity of the joint. The entire surface of the membrane is occasionally covered with these bodies, which are of a white or yellowish colour, and very variable in size and shape; the smallest presenting the form of villi not much larger than those of the jejunum, the largest having somewhat the magnitude and appearance of the appendices epiploicæ of the large intestine, while many of an intermediate size approach in appearance to a lemon-seed. In some instances the membrane is only partially pervaded by them, and they are not unfrequently arranged like a fringe around the edge of the articular surfaces. They are generally very smooth on the surface, which appears to be perfectly continuous, if not identical, with the synovial membrane. Their attachment is frequently broad, and occasionally very narrow and pedunculated, often merely filamentous, so that a little further thinning of the part, or slight force acting on the body, would remove it from the capsule, and throw it loose into the cavity of the articulation. The disease has been most frequently seen in the knee, and sometimes in the elbow. The affection is obscure in its nature; it is slow in its progress; the joint is the seat of pain after and during exercise, probably from the morbid processes interfering with the motions of the articular surfaces. As the disease advances, the joint becomes swelled and elastic, unattended generally by ulceration of the tissues within or around it. In examining the part, when the articular surfaces are moved on each other, it will be found that their motion is more or less interfered with; and considerable irregularity in their action may be felt by the hand placed firmly on the joint during the procedure.