FEVERS. 527 



the series and succession of symptoms. " Thus, fever is often 

 joined with phlegmasia, as in the Synochus pleuritica, or the Feb- 

 ris pleuritica o Sydenham, in which it was plain that the fever 

 was the primary disease, upon which the other supervened, and 

 which passed away when the original fever subsided. This was 

 a clear instance of a fever in its own nature free from phlegma- 

 sia, yet combined with it ; but frequently cases occur where it is 

 difficult to distinguish which is the idiopathic or primary dis- 

 ease ; and as this is a matter of importance we shall pay some 

 attention to it. 



" Whether the phlegmasia, then, is the primary disease may 

 be determined from the following considerations : First, By the 

 season of the year ; in the spring phlegmasiae are frequent and 

 commonly epidemic ; in the autumnal season pure fevers pre- 

 vail. At the same time this will not entirely determine the 

 question, because towards the end of autumn, when the cold 

 sets in, the phlegmasiae re-appear. Secondly, By the symptoms 

 which first appear ; thus, if the inflammatory symptoms first 

 take place, we have reason to look upon the phlegmasia as the 

 primary disease, if otherwise, we conclude the fever to be pure. 

 In the case of a pleurisy, for instance, it may perhaps be said 

 that there is often some fever subsisting for twenty-four hours 

 before the characteristic symptoms appear ; but this will not 

 be found to be the case if we look carefully. If the fever sub- 

 sists for several days without the inflammation, it will be reason- 

 able to suppose that the fever is the primary disease. Thirdly^ 

 Where the fever and the inflammatory symptoms are simultane- 

 ous, it may be determined by the knowledge of the epidemic 

 which prevails. Thus the symptomatic pleurisy of Sydenham 

 was ascertained by this, that the inflammatory symptoms, as 

 he says, supervened, being no part of the original epidemic ; and 

 further, these accidental symptoms disappeared while the origin- 

 al febrile epidemic constitution remained. Fourthly, By the ex- 

 acerbations and remissions being more regular and evident, 

 when the fever is idiopathic. I have mentioned as a fact, that 

 fevers attended by inflammations are always continued. So, in 

 the Synochus pleuritica of Sauvages, he had that mark that the 

 pleurisy sometimes was removed when the fever ran its course. 

 These marks may serve to determine the nature of such com- 



