Lastly the Roentgen radiograms of.the two affections are of a totally different appearance: in gout the uratic deposits are permeable to the Roentgen rays, and do not show, therefore, in the photo graph; the bone-heads of the diseased joint appear in clear outline, a distinct, clear space representing the cavity of the joint and the cartilages. In rheumatic gout the heads of the bones always ap pear obscure and deformed; even in acute cases, or when much mobility of the affected joint is still left, the photo gram looks as if the two bony heads were melting together.
Locouo'ron ATAXIA. — In tabes and other serious nervous affections the joints may be diseased in a manner much re sembling rheumatoid arthritis; in such eases the Roentgen photogram is of great value; when the affection is due to le sions of the nervous system, rapidly progressing absorption is found in the bones, and only portions of the bones are visible in the phctogram, while large portions of them have totally disap-• peared.
The points of special significance in the diagnosis of rheumatoid arthritis are: I. The sex and age of the patient.
2. The soft spindle enlargement of the finger-joint and the swelling of the wrists; together these form the most constant symptom, and in nine cases out of ten the disease can be easily and cer tainly diagnosed from the hand alone.
3. The cold, sweating pains. 4. The af fection of the jaws and neck. 5. The cachexia and wasting. And, of less im portance: 6. Pigment-changes. 7. Tachy cardia. Gilbert A. Bannatyne, Arthur S. Wohlmann, Frank R. Blaxall (Lancet, Apr. 25, '96).
There is a disease occurring in chil dren before the second dentition which is characterized clinically by elastic, fusi form enlargement of joints, without bony change, and also by enlargement of the glands and spleen.
The disease has hitherto been called rheumatoid arthritis, but it differs from that disease in adults clinically in the absence of bony change even when no disease is advanced, and in the enlarge ment of glands and spleen, and patho logically in the absence, even in advanced cases, of the cartilaginous changes, which are found quite early in that disease, and also in the absence of osteophytic . change. Still (Medico-chir. Trans., '97).
Etiology. — Authors have disagreed very much regarding the etiology of this disease. Some have held it to be a ondary affection, consecutive upon acute articular rheumatism, while others have connected it with gout or believed it to be a senile change of the joints. Again,
others have argued that it is caused by some abnormal nerve-condition having its seat in the cord or in the peripheral nerves. Recently, however, the prevail ing view has been that the disease is caused by bacteria, though the specific bacterium of the disease has not been recognized. Indeed, it is possible that several dissimilar varieties of bacteria may have a similar effect on the tissues of the joints.
German authors still maintain that some few cases are dependent on a true rheumatic infection and develop in di rect continuation of an acute rheumatic disease. For such cases Baumler pro poses to reserve the denomination "chronic rheumatism of the joints"; but he admits that they are of rare oc currence; and other authors, including myself, have never observed any case in which the affection was proved to have commenced with an attack of acute ar ticular rheumatism. The second group of cases, representing an overwhelming majority and recognized by German authors as "polyarthritis deformans" (identical with the rheumatoid arthritis or rheumatic gout of the English and American authors) is, by general con sent, attributed to the invasion of a specific bacterium. This view is sup ported by much evidence: the disease begins in one or a few joints and spreads from there not only to other joints, but also to the nerves, the heart, the muscles, and the skin. It often occurs as a con tinuation of other infectious diseases, such as influenza, tonsillitis, typhoid, etc. Bannatyne notes that in 25 per cent. of all cases there was a history of disease of the female organs of genera tion and in 20 per cent. catarrh of the gastrointestinal or respiratory mucous membranes. I have made the same ob servation; in many cases the patients confidently consider influenza or dis eases of the female organs of generation as the cause of the affection; in some cases it had developed in direct continu ation of puerperal affections.
All authors agree that cold and damp rooms, especially when used as sleeping chambers, are predisposing to the de velopment of rheumatoid arthritis; these conditions certainly favor the develop ment of micro-organisms and their in vasion into the body.