PHYSIOLOGY. 



PHYSIOLOGY is a science which treats of the phenomena or 

 functions whose union constitutes life. These functions may 

 be distinguished into those which are intended to connect the 

 living being with the surrounding world ; these are called 

 functions of relation, and belong only to animals : and those 

 whose object is the preservation of the individual ; these are 

 common to vegetables and animals, and are called functions 

 of nutrition. The instruments by means of which the func- 

 tions are accomplished are denominated organs. Several of 

 these united for the same end form an apparatus. Finally, 

 considered as a whole, they constitute an organization. 



The organization, which is an intimate union of form and 

 matter, is continually traversed by fluids, whose province 

 is, to convey nourishment to the organs, and to take up, for 

 the purpose of carrying off, what is useless. This twofold 

 movement of composition and decomposition is termed nutri- 

 tion. The first of these two forces, composing nutrition, is 

 called absorption; the second bears the generic name of 

 secretion. 



Thus the three great functions of nutrition do but prepare 

 and carry off the elements which, as a final result, are ab- 

 sorbed or secreted. Organized beings have been divided into 

 animate beings, or such as are possessed of sense and motion ; 

 and inanimate beings, or such as are deprived of both these 

 faculties. The power of spontaneous movement in animals 

 requires essential modifications of organization : hence are de- 

 rived in them the characters of the three great functions of 

 nutrition, viz. the circulation, the respiration and the diges- 

 tion. 





