PREFACE. ix 



investigation ; for every blacksmith, groom, and 

 stable boy, not only conceives himself, but is 

 often believed by his employer to be fully 

 competent to the important task of curing 

 diseases, of the nature of which he is totally 

 ignorant. 



Surely nothing can be more absurd than 

 to imagine that a groom, by having fed and 

 cleaned a horse for a few years, must conse- 

 quently become acquainted with his diseases 

 and their causes; it would be equally plausible 

 to assert, that because he knows by ocular ex- 

 perience, that the sun rises in the morning and 

 sets at night, he must be an astronomer. The 

 majority of the affluent, to avoid tlie trouble of 

 reflection, suffer themselves to be influenced in 

 matters of this nature by men, whose opinions 



on 



