CASE III. Maria Genette was received into the Hotel-Dieu, in consequence of a fall on the great trochanter. She had been attacked by a pain in the joint of the thigh of the same side. Walking, which was performed with difficulty, augmented the pain, and standing, though more tolerable, could not be long continued. The thigh was evidently longer than the other. To leave the disease to nature, and confine the patient to a state of rest, constituted the practice of Desault. What effect could the external use of astringents, recommended by Petit, produce in such a disease? Some time after her admission, the patient was attacked by dysentery, in consequence of which she was removed to the medical ward, where she died. On opening the body, the parts in the neighbourhood of the joint were evidently tumefied, and the capsule was stretched from above downwards. The head of the os femoris was situated on the external edge of the acetabulum. The capsule, though greatly elongated was still in a state of tension; and the articular cartilage was swollen to such a degree, as nearly to fill up the cavity. The quantity of synovial fluid was less than natural. 7. This case, taken at a period of the disease not far advanced, fully confirms the inference deducible from the two preceding ones, respecting the cause of spontaneous luxations. Here, indeed, the capsule not having given way, the swelling having only just commenced, and the synovia existing in but small quantity, the progress of nature was evident. Here, also, occurred a sign not noticed by Petit; namely, the elongation of the limb, which always, in such cases, precedes its contraction. From what we have said, it appears, 1st, that the efficient cause of spontaneous luxations of the os femoris, is a swelling of the articular cartilages, which alters and destroys their organization: 2dly, that the presence of this swelling must necessarily render fruitless all attempts that might be made to replace the head of the bone in its cavity: 3dly, that the change in the organization of the cartilages, renders astringents, discutients, and other external means applied for the purpose of removing the tumefaction, entirely useless: 4thly, that here, as in many other cases, art ought to confine itself to the palliation of effects, and not attempt the removal of causes. MEMOIR XIII. ON THE FRACTURE OF THE ROTULA. § I.