2G8 INFLUENCE OF THE CIRCULATION 



motory phenomena centring in it, may continue for 

 some time after the total cessation of the circulation 

 of the blood. 



That impressions to and from the centres of 

 sensorial and motor power, are conveyed along the 

 cerebro spinal nerves, which are passive conductors 

 of those impressions : 



In reference to the special physiology of the 

 cerebro-spinal nerves: 



1. The researches of Sir Charles Bell have shown 

 that the nerves proceeding from the spinal cord are 

 anatomically and functionally compound, and that of 

 the fibres constituting each nerve some are instru- 

 ments of sensation, others of voluntary motion. 



2. The demonstration of the special motor func- 

 tion of the spinal cord by Dr. Marshall Hall, renders 

 it probable that purely excito-motory phenomena or 

 involuntary muscular contractions are produced by 

 impressions transmitted along nervous filaments inti- 

 mately, if not exclusively, connected with the spinal 

 cord. 



3. The recent experimental investigations of Mat- 

 teuci, moreover, tend to confirm previous ideas on 

 the subject, in rendering it highly probable that the 

 nervous power, which produces involuntary muscular 

 contractions, is in its essential nature a physical force 

 nearly allied to electricity. 



All these researches merely assign to the cerebro- 

 spinal nerves the power of passively conducting 

 sensorial and motific impressions as a wire con- 

 ducts electricity ; and they further assume, that 

 as long as each nerve is structurally whole, and 



