The acute form of rheumatoid arthritis closely resembles the milder varieties of acute articular rheumatism or the best marked examples of the subacute form of that disease. But it presents the following particulars, by which it may generally perhaps, but not always, be distinguished: while the temperature, the thirst, the furring of the tongue, the frequency of the pulse, the articular pains and tenderness, etc., are less developed than in acute articular rheumatism, there is wanting the profuse and continued perspiration, the early involvement of the endo- or pericardium in the inflammation, and the prompt prostration of the strength so commonly witnessed in that disease. On the other hand, while the rheumatoid affection may involve the larger joints--knees, ankles, elbows, and wrists--it almost certainly implicates the smaller joints of the fingers, and often of the toes. There is apt to be greater effusion into the synovial capsules (McLeod's capsular rheumatism) and into the synovial sheaths and bursæ about the affected joints than in ordinary acute or subacute rheumatism; further, the inflammation does not migrate from joint to joint, but obstinately persists in several of them, and more especially in the wrist and in the metacarpo-phalangeal joints of the index and middle finger, perhaps also in the ankles and in the metatarso-phalangeal articulation of the great toe. Instead of disappearing in four to six weeks, the articular inflammation continues, although the pain may abate very much, and the capsules of the joints continue swollen and rather tense. The muscles of the extremities waste, and are the seat of painful reflex spasms which interfere with the movements of the joints; and although the patient is capable of moving about, and is free from all febrile disturbance, one or several of his joints remain permanently swollen, painful, and crippled. Perfect restoration of all the affected joints seldom if ever occurs. In common with other observers, I have met with this acute form most frequently in young women twenty to thirty years of age--several times in connection with recent delivery or rapid child-bearing, or lactation; once after what was regarded by the medical attendant as an attack of acute rheumatism occurring not long after labor. It has been observed in children, and is not uncommon after forty. These patients usually suffer in their general health--become weak, pale, depressed in spirits, and lose flesh. In several cases of this form marked intervals of improvement have occurred; the local disease has ceased to progress, and tolerable comfort has been experienced, perhaps, till pregnancy, delivery, or lactation again determined a fresh outbreak of the disease. Sometimes, however, this acute form steadily advances, and in a year or two establishes changes in the cartilaginous and osseous structure of the affected joints. Such a case I met in a lady of twenty-one who had had a good deal of anxiety as a mathematical