On the other hand, a large proportion of cases run a more irregular and protracted course, and more or less marked relapses succeed real but temporary improvements, the local disturbance affecting fresh joints or reappearing in those previously attacked, and the general symptoms resuming renewed activity. The duration of the active symptoms in these cases is considerable, seldom under six weeks, and frequently occupying seven, eight, or more. In these protracted cases the symptoms, as a rule, are usually rather milder, the perspiration not as profuse or sour, the urine of less density and acidity, the articulations less hot and painful, than in the previously described group. Sometimes, indeed, the perspiration and the urine are of neutral or even faintly alkaline reaction. It is not only the unexplained tendency to relapse which protracts these {45} cases, but sometimes in addition an established proclivity to the disease--the rheumatic habit--or a condition of previous unsound or frail health. Such cases occasionally pass into the subacute form, or the mild febrile symptoms gradually and finally decline, and the joints may either remain tender, swollen, and stiff some time longer, or these signs of recent inflammation may soon disappear and leave the articulations merely weak. Many cases of acute rheumatism embody several of the features of the two groups just described, and no definite course or duration of acute articular rheumatism can be accurately laid down. The course and duration of acute polyarticular rheumatism have received a good deal of attention of late years. But Dr. Austin Flint[110] was one of the first to study the natural history of the disease uninfluenced by active treatment, and he was followed in 1865,[111] 1866,[112] and 1869[113] by Sir William Gull and Dr. Sutton, who treated a series of cases without medicine, unless mint-water be so regarded. The mean duration of Flint's 13 cases from the date of attack to convalescence, excluding one in which pericarditis and pneumonia occurred, was a fraction under twenty-six days. It is unfortunate that the number of cases was so small, and that 11 of the patients were females, who appear to be especially subject to the milder and more protracted attacks of the disease. A larger number, with an equal proportion of the sexes, would probably have given a different result. [Footnote 110: _American Journal of Med. Sciences_, July, 1863.] [Footnote 111: _Ib._, vol. xii.] [Footnote 112: _Medico-Chirurgical Transactions_, vol. lii.] [Footnote 113: _Guy's Hospital Reports_, 2d Series, vol. xi.]