+Symptoms.+ The symptoms of arthritis are obviously more severe than those of a simple articular synovitis and are both local and general. The general symptoms arise from the absorption into the circulation of either bacteria or their toxins, and vary greatly in severity. There is either a toxemia or a septicemia, with the usual symptoms of a general sepsis. The local symptoms are those common to synovitis and arthritis: pain, tenderness, swelling, heat, redness and loss of function. From these alone a differential diagnosis between synovitis and arthritis cannot be made. If, however, there is a sensation of crepitus conveyed to the examiner’s hand upon passive motion, there is an arthritis present beyond doubt. This symptom is due to the destruction of the synovial covering of the bone ends involved, permitting contact of bone with bone. It is more common to chronic joint disease, but may also accompany acute conditions, especially if they are severe. Symptoms peculiar to the variety of infection and the history as to duration, causation, course and number of joints involved, must be considered in making a diagnosis or prognosis. +Varieties.+ Besides simple traumatic arthritis, there are many constitutional disorders which affect the joints conspicuously; these are: tuberculosis, syphilis, gonorrhea, gout and rheumatism. A prominent cause of many instances of arthritis heretofore regarded as rheumatic in origin, is now known to exist in any area of infection. Such “foci of infection” discharge a certain amount of infective material into the circulation, which may find lodgment in a joint and set up an acute process. It has been proven in numerous cases that a so-called rheumatism will yield promptly to drainage of a chronic abscess, no matter how remote the location. Oral conditions especially have been found responsible for this form of arthritis. Abscesses at the apexes of teeth and pyorrhœa alveolaris, when properly operated, yield nothing short of miracles, in the way of relieved symptoms. In addition to the varieties of arthritis already mentioned, those due to certain infectious diseases, such as measles, scarlet fever, typhoid fever, smallpox or erysipelas, should be included, as well as cases of neuropathic origin. +TRAUMATIC ARTHRITIS+ +Nonpenetrating and Penetrating+ +Nonpenetrating.+ Ordinary contusions or twisting at a joint, may result in the establishment of an inflammatory process within the joint, evidenced by much swelling and giving the sensation of fluctuation to the examining hands, indicating the presence of fluid within the synovial membrane. This occurs also when there is a detached fibrocartilage in the joint. The synovial membrane is thickened and there is an exudation of serum. Sprains belong in this classification. These are simple, clean, inflammatory conditions. +Symptoms.+ These are generally limited to those enumerated as belonging to synovitis, except that the disability is more pronounced.