256 THE VITAL FUNCTIONS. 



many different parts: they may be considered, therefore, as 

 performing, with regard to the vital functions, an office ana- 

 logous to that which the brain and spinal marrow perform 

 with regard to the other nerves, or as being secondary cen- 

 tres of nervous power. Thus, there are two important ob- 

 jects for which the nerves belonging to the ganglionic sys- 

 tem have been provided; first, to serve as the channels 

 through which the affections of one organ might be enabled 

 to influence a distant organ; and secondly, to be the medium 

 through which the powers of several parts might be com- 

 bined and concentrated for effecting particular purposes, re- 

 quiringsuch co-operation. Hence it is by means of the gan- 

 glionic nerves that all the organs and all the functions are 

 rendered efficient in the production of a common object, and 

 are brought into one comprehensive and harmonious system 

 of operation. 



The nervous power, the effects of which we are here con- 

 sidering, should be carefully distinguished from that power 

 which is an attribute of another portion of the nervous sys- 

 tem, and which, being connected with sensation, volition, 

 and other intellectual operations, has been denominated sen- 

 sorial power.* The functions of digestion, circulation, ab- 

 sorption, secretion, and all those included under the class of 

 nutrient or vital functions, are carried on in secret, are not 

 necessarily, or even usually attended with sensation, and 

 are wholly removed from the control of volition. Nature 

 has not permitted processes, which are so important to the 

 preservation of life, to be in any way interfered with by the 

 will of the animal. We know that in ourselves they go on 

 as well during sleep as when we are awake, and whether 

 our attention be directed to them or not; and though occa- 

 sionally influenced by strong emotions, and other affections 

 of mind, they are in general quite independent of every in- 

 tellectual process. In the natural and healthy condition of 



* This distinction has been most clearly pointed out, and illustrated by Dr. 

 A. P. W. Philip. See his "Experimental Inquiry into the Laws of the Vi- 

 tal Functions," 



