A DISSERTATION 



TUNCTIONS OF THE NERVOUS SYSTEM. 



INTRODUCTION. 



The nervous system^ in which term we comprise the cere- 

 brum, cerebellum, medulla oblongata, and medulla spinalis, and 

 the nerves thence distributed throughout the whole body, is of 

 all organs of the animal economy the most important. It is 

 the seat of the rational soul, and the link by which it is united 

 to the body ; it is the instrument by which the soul, so long 

 as it is united to the body, produces its own actions, termed 

 animal, and by which it acts on the rest of the body, and the 

 body in turn acts upon it. But, however great may be the 

 importance of the nervous system in these respects, it is of fur- 

 ther importance, because it possesses in addition the singular 

 faculty of exciting in the human body various movements with- 

 out the consciousness or assistance of the soul; nay, plainly against 

 its will it can and does excite them without intermission through 

 the whole of life. The nervous system also influences other 

 functions of the human body, as digestion, nutrition, and secre- 

 tion, which functions do not remain long undisturbed if the 

 nerves be injured. I say nothing of the share which the 

 nervous system is well known to have in almost every disease. 



Prom all this it is manifest how valuable results would follow 

 on sedulous inquiry into the structure and functions of the 

 nervous system, inasmuch as much light might be expected 

 to be thrown on medical art; nor ought it to be lightly 

 esteemed as to its results, with reference to those who desire to 

 know themselves. For he who desires to understand more 

 thoroughly his own mind, — the nobler portion of himself, — can 

 understand it only from its operations. But these are never 



