OBJECTS OF PHYSIOLOGY. 15 



becomes frozen and stiff like the inanimate masses 

 by which it is surrounded. 



Here, then, is a grand boundary-line dividing the 

 organized from the inorganized, the animate from 

 the inanimate body. Chymistry and natural phi- 

 losophy investigate the laws and conditions which 

 regulate the action and movements of inanimate or 

 inorganized objects ; but, from what we have seen 

 of the power of the vital principle in modifying 

 these, it will be manifest that, however extensive 

 and accurate our knowledge of the properties of the 

 elementary materials of living bodies may be, con- 

 sidered separately, we can thence infer nothing in 

 regard to the qualities of the animal compound when 

 endowed with life, but must resort to observation 

 and study for the discovery of the conditions by 

 which life is characterized, and under which it is car- 

 ried on. 



Physiology, or the history of the functions which 

 characterize living- beings, is thus a subject of pecu- 

 liar interest ; and human physiology, or that which 

 is about to engage our attention, is as important in 

 its practical consequences as it is attractive to 

 rational curiosity. In its widest sense it compre- 

 hends an exposition of the functions of the various 

 organs of which the human frame is composed ; of 

 the mechanism by which these are carried on ; of 

 their mutual relations to each other; of the means 

 of improving their development and action; of 

 the purposes to which they ought severally to be 

 directed ; and of the manner in which exercise ought 

 to be conducted, so as to secure for the organ the 

 best health, and for the function the highest effi- 

 ciency. A true system of physiology comes thus 

 to be the proper basis, not only of a sound physical, 

 but of a sound moral and intellectual education, and 

 of a rational hygiene ; or, in other words, it is the 

 basis of every thing having for its object the 

 physical and mental health and improvement of 



