ANIMAL AND VEGETABLE 

 PHYSIOLOGY. 



PART II. 



THE VITAL FUNCTIONS. 



Chapter I. 



OBJECTS OF NUTRITION. 



The mechanical structure and properties of the 

 organized fabric, which have occupied our atten- 

 tion in the preceding volume, are necessary for 

 the maintenance of life, and the exercise of the 

 vital powers. But however artificially that fabric 

 may have been constructed, and however admi- 

 rable the skill and the foresight which have been 

 displayed in ensuring the safety of its elaborate 

 mechanism, and in preserving the harmony of 

 its complicated movements, it yet of necessity 

 contains within itself the elements of its own dis- 

 solution. The animal machine, in common with 



VOL. II. B 



