156 NATURE AND MAN. 



science ; and when all these preparatory steps have been taken, 

 the student will enter upon its study with no small advantages. 



Whatever may be thought of the expediency of commencing 

 the study of anatomy by investigating the structure of the simplest 

 organisms, a plan which has many advocates, we are decidedly of 

 opinion that this course is essential in physiology ; and that the 

 student who adopts it will be saved the necessity of unlearning 

 many erroneous notions which he would unavoidably imbibe from 

 the premature study of the human functions. In the pursuit of 

 general physiology he will learn what are the essential conditions 

 of life ; he will see the changes indispensable to its support mani 

 fested in their simplest circumstances ; and he will be able to 

 ascertain what structures are necessary to their performance, and 

 what additions and modifications these may undergo to suit the 

 various purposes of their existence. He will acquire, also, the 

 great advantage of making observation a substitute for experiment ; 

 the former means, wherever it can be employed in physiology 

 being decidedly preferable (as we hope we have successfully de 

 monstrated), both in the certainty and satisfactory nature of the 

 conclusions which may be drawn from it ; and in its freedom 

 from those objections which every humane mind must feel to the 

 infliction of unnecessary tortures upon beings endowed with 

 sensations as acute as our own. 



We have alluded, in the early part of this article, to the diffi 

 culty of distinguishing the operation of vital and physical laws 

 and this we cannot but regard as a question to be completely 

 determined before the laws of purely vital phenomena can be 

 satisfactorily established. To analyze the phenomena in which 

 physical laws are acting under conditions supplied by vital pro 

 cesses, and to trace the diversities from their usual mode of action 

 occasioned by the existence of these conditions, appears to us, 

 therefore, to be at present the most obvious method of advancing 

 the science. We cannot but believe that the inquiry would 

 ultimately terminate in referring all vital actions to properties 

 as essentially connected with that form of matter which we call 

 organized, as are the ordinary physical properties with inorganic 

 matter. 



One more question would then remain : is it possible that these 



