Vlll 



PREFACE. 



analagy ; which, fo long as it is concerned in compar- 

 ing the eflential properties of bodies, leads us to many 

 and important difcoveries ; but when with licentious ac- 

 tivity it links together objeds, otherwife difcordant, by 

 fome fanciful fimilitude ; it may indeed colled orna- 

 ments for wit arid poetry, but philofophy and truth re- 

 coil from its combinations. 



The want of a theory, deduced from fuch ftrict anal- 

 ogy, to conduct the practice of medicine, is lamented by 

 its profeflbrs ; for, as a great number of unconnected 

 fads are difficult to be acquired, and to be reafoned from, 

 the art of medicine is in many inftances lefs efficacious 

 under the direction of its wifeft practitioners ; and by 

 that bufy crowd, who either boldly wade in darknefs, or 

 are led into endlefs error by the glare of falfe theory, it 

 is daily pradifed to the deftrudion of thoufands ; add 

 to this the unceafmg injury which accrues to the public 

 by the perpetual advertifements of pretended noftrums \ 

 the minds of the indolent become fuperftitioufly fearful 

 of diieafes, which they do not labour under ; and thus 

 become the daily prey of fome crafty empyric. 



A theory founded upon nature, that fhould bind to- 

 gether the fcattered fads of medical knowledge, and con- 

 verge into one point of view, the laws of organic life, 

 would thus on many accounts contribute to the intereft 

 of fociety. It would capacitate men of moderate abili- 

 ties to pradife the art of healing with real advantage to 

 the public ; it would enable every one of literary ac- 

 quirements to diftinguifh the genuine difciples of medi- 

 cine from thofe of boaftful effrontery, or of wily addrefs ; 

 and would teach mankind in fome important fituations 

 the knowledge of themf elves. 



There 



