INTRODUCTION. Xlll 



not because we should be disposed to doubt the 

 observations of an individual engaged in experi- 

 mental inquiries, but because the reasoning which 

 he founds, or the principles which lie deduces from 

 important results, are occasionally far from being 

 either legitimate or correct. 



The experimentalist seldom commences his 

 practical inquiries without having some precon- 

 ceived view or principle to establish or refute, 

 tending to direct these studies ; and whatever be 

 the nature of the conclusions,he is apt to seize and 

 apply with avidity such only as are consonant with 

 his own opinion. Although the reader is not 

 liable to be blinded by the feelings and train of re- 

 flection which regulate the proceedings of the 

 experimentalist, yet he is liable to be biassed by 

 the plausible manner which generally accom- 

 panies the statement of simple facts, on account 

 of the variety of views which are closely inter- 

 woven with them. 



The experiments of WILSON PHILIP, advanced 

 to prove his peculiar opinions in regard to ani- 

 mal heat and digestion, are the best illustrations 

 that can be brought forward to shew that expe- 

 riments themselves, although correct, are occa- 



