PREFACE. 



1 HE purport of the following pages is an endeavour 

 to reduce the fa&s belonging to Animal Life into 

 claffes, orders, genera, and fpecies ; and, by comparing 

 them with each other, to unravel the theory of difeafes. 

 It happened, perhaps unfortunately for the inquirers in- 

 to the knowledge of difeafes, that other fciences had re- 

 ceived improvement previous to their own ; whence, in- 

 ftead of comparing the properties belonging to animated 

 nature with each other, they, idly ingenious, bufied them- 

 felves in attempting to explain the laws of life by thofe 

 of mechanifm and chemiftry ; they confidered the body 

 as an hydraulic machine, and the fluids as pafling through 

 a feries of chemical changes, forgetting that animation 

 was its eflential chara&eriftic. 



The great Creator of all things has infinitely diver- 

 fified the works of his hands, but has at the fame time 



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