synonymous with rheumarthritis chronica, rheumatisme articulaire chronique simple (Besnier), polyarthritis synovialis chronica (Heuter), is defined here as a chronic idiopathic inflammation of one or a few articulations, which is more prone to become fixed than the acute form, and which, notwithstanding its protracted duration, produces no profound structural alterations in the joints. ETIOLOGY.--It may be the direct sequel of a single attack or more {70} commonly of several attacks, of acute, or more especially of subacute, articular rheumatism. But it is generally a primary affection, occurring in persons who have not had either acute or subacute rheumarthritis, yet owning the same causation as these, and occasionally in its course exhibiting acute or subacute symptoms. The specially predisposing conditions are inheritance; repeated attacks of subacute or acute articular rheumatism, which in accordance with general laws impair the resisting power of the affected joints; prolonged residence or employment in cold, damp, or wet rooms or localities; repeated exposure to bleak, cold currents of air or to frequent wettings of the body or lower limbs. For these reasons it is most common amongst the poor, who are especially exposed to the influences just mentioned; and amongst them cellar-men and sailors, washerwomen and maid-servants, are very liable to the disease. It is chiefly an affection of advanced life, or at least of mid-age, and is rare in youth. The first attacks, and especially exacerbations, are apt to be induced by the direct action of a draught of cold air or by unusual exposure to cold and damp air, especially when the body has been fatigued or overheated. In many cases no distinct exciting cause can be traced.