ANIMAL AND VEGETABLE 

 PHYSIOLOGY. 



PART IL 



THE VITAL FUNCTIONS. 



Chapter L 



objects of nutrition. 



i HE mechanical structure and properties of the 

 organized fabric, which have occupied our attention 

 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 admirable the 

 skill and the foresight which have been exercised 

 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 dissolution. The animal 

 machine, in common with every other mechanical 

 contrivance, is subject to wear and deteriorate by 

 constant use. Not only in the greater movements 

 of the limbs, but also in the more delicate actions 



VOL. II. B 



