INTRODUCTION. 



I. IN teaching the Practice of Physic, we endeavour to give 

 instructions for discerning, distinguishing, preventing, and 

 curing diseases, as they occur in particular persons. 



" I say that we teach to cure diseases as they occur in particu- 

 lar persons, in order to distinguish the course of the Practice 

 from that of the Institutions. In the Institutions certain gen- 

 eral doctrines with regard to health, disease, and remedy, are 

 delivered ; whereas what we call the Practice is the medical art 

 applied to particular diseases and persons." 



II. The art of Discerning and Distinguishing diseases may 

 be best attained by an accurate and complete observation of 

 their phenomena, as they occur in concourse and in succession ; 

 and by constantly endeavouring to distinguish the peculiar and 

 inseparable concurrence of symptoms, to establish a Methodical 

 Nosology, or an arrangement of diseases according to their 

 genera and species, founded upon observation alone abstracted 

 from all reasoning. Such an arrangement I have attempted in 

 another work, to which, in the course of the present, I shall 

 frequently refer. 



" It is certain that there is a peculiar congeries of phenomena 

 or symptoms constituting diseases in individuals. It must also 



