482 PRACTICE OF PHYSIC. 



these fevers more fully, and with enumerating all the pheno- 

 mena belonging to them. 



"But this has always been a difficult matter; and the rock upon 

 which the classical writers have always split has been in giving 

 the history of a class instead of that of a genus, a method which 

 is attended with much fallacy. We are not safe in delivering 

 the history of even the lowest genus; but we are in still greater 

 danger when attempting a higher genus. We can never be 

 secure in our description unless we constantly keep in view a 

 particular species, or what truly and certainly happens in na- 

 ture, as in every artificial combination there is danger of our 

 being misled. We therefore keep in view the Febres strictius 

 dictse, their first section, the intermittent, and of this the first 

 genus, the tertian, which I consider as single. And now that 

 we are to enter upon the first article, and to give its history or 

 description, you will attend to the difference between a defini- 

 tion and a description. A definition or character implies so 

 many particulars, or mentions so many phenomena as are just 

 necessary to distinguish one disease from other diseases. But 

 besides these, every disease is accompanied by a great number of 

 other phenomena, which are variously combined, and appear in 

 different orders of succession. The enumeration of both these 

 kinds of phenomena is necessary to form a proper description. 

 From a neglect of this distinction, and from taking the genus 

 for the species, authors have thrown a great many superfluous 

 circumstances into their definitions, and these not well arranged. 

 But here I hope to give an example of a history or description, 

 which is at once full and sufficiently distinct in its several parts." 



X. The phenomena to be observed in such a paroxysm are 

 the following : The person is affected, first, with a languor or 

 sense of debility, a sluggishness in motion, and some uneasiness 

 in exerting it, with frequent yawning and stretching. At the 

 same time, the face and extremities become pale, the features 

 shrink, the bulk of every external part is diminished, and the 

 skin over the whole body appears constricted, as if cold had 

 been applied to it. At the coming on of these symptoms, some 

 coldness of the extremities, though little taken notice of by the 

 patient, may be perceived by another person. At length the 

 patient himself feels a sensation of cold, commonly first in his 



