FEVERS. 513 



the sooner repeated ; and therefore that the cause of the fre- 

 quent repetition is to be sought for in the cause of the protrac- 

 tion of paroxysms. 



" Having formed this conclusion, I proceed upon it, that 

 every fever consists of repeated paroxysms, and that the funda- 

 mental division of fevers is that into intermittent and continued, 

 or into such as have separate paroxysms, and such as have them 

 most obscurely formed; between which there are all the inter- 

 mediate states. 



" We next proceed to inquire into the cause and nature of 

 these different forms of fever ; and, first, as there are intermit- 

 tents which occur at different intervals at first, particularly the 

 three forms of Quotidian, Tertian, and Quartan, there immedi- 

 ately occurs to us the notice of a particular fact, viz. that the 

 paroxysm of a quartan is constantly of shorter duration than 

 that of a tertian ; and the paroxysm of a tertian is of shorter 

 duration than that of a quotidian. From this it appears, that 

 the shorter the paroxysm is, the longer is the interval, and, con- 

 sequently, the longer is the intermission with respect to the pa- 

 roxysms. Thus, if the paroxysm of the quartan be five or six 

 hours, it leaves for the intermission about sixty-six hours, which 

 is a great part of the seventy-two ; and thus the tertian leaves 

 about forty hours of an intermission. 



" This suggests to us what perhaps is an important con- 

 clusion, that the recurrence of paroxysms does not so much de- 

 pend upon the nature of the fevers as upon the duration of 

 those paroxysms which do occur ; and therefore that the parti- 

 cular form which the fever takes, one being tertian, another 

 quartan, and a third quotidian, may be considered as depend- 

 ing upon the duration of the paroxysms once formed ; the 

 longest intervals being universally connected with, and evident- 

 ly depending upon, the shortest paroxysms, and vice versa. 

 This, I say, is a considerable step in the doctrine of fevers, as 

 it establishes the general difference between intermittents and 

 continued fevers. As every fever whose paroxysm is protract- 

 ed eighteen hours or longer, must necessarily have a quotidian 

 recurrence, if this fever again, from any cause, be protracted to 

 twenty-four hours, it can have no intermission, as it must have 

 a recurrence at this period ; and therefore such a fever must 



