DISEASES OF THE NERVOUS SYSTEM. 



By W. H. HARBAUGH, V. S., Richmond, Va. 



lu a work of this kind anything approaching a detailed description 

 of the anatomy and physiology of this subject is simply out of the 

 qu< -stion, as the space it would require forbids the attempt; but a few 

 of the important points will be noticed so that what follows will be 

 better understood. 



The nervous system is the distinguishing feature of animal life; with- 

 out it there can be no intelligence, no instinct, no sensibility, no per- 

 ception : in fact, existence would be nothing more than vegetable life. 



The senses touch, taste, sight, hearing, smell all depend on the 

 nervous system. Motion depends on it. A muscle can not contract 

 without receiving the stimulus from the nervous system. For example, 

 if a nerve passing from a nerve center to a muscle is severed, the par- 

 ticular muscle that is supplied by the cut nerve is paralyzed. 



In the living animal the muscle is the power; but without the stimu- 

 lus it receives from the nerves it is powerless. The muscle and the 

 nerve, in their relationship, may be compared to the powder and the 

 match in a blast. The hole drilled into the rock may be packed with 

 j:i;tut powder, the fuse maybe in readiness, but the powder can not 

 rend the rock unless the match is applied to the fuse. The nervous 

 M >tem originates and conveys the stimulus or impulse which excites 

 the muscle. The contraction of the muscle is the source of movement. 



lu the description of the blood it is stated that all nutrition and 

 all vitality depend on the blood and, although the nervous matter 

 receives its nutrition from the blood, the blood is only capable of 

 fulfilling its proper functions by the aid of the nervous system 

 Without nervous stimulus the heart can not beat. All the other systems 

 in the body are excited and regulated by the nervous system. 



The nervous system, for various reasons, is studied in two divisions, 

 but it must be Inmie in mind that the two divisions are closely con- 

 nected one with the other. 



The cerfbro-nphial diriftion consist* of the brain and spinal cord, 

 nerves, and ganglia. The nerves of this division convey the impulses 

 of motion and sensation, and supply all parts which arc under the con* 



ill 



