NERVE 



67 



position, far from the pole, acts upon more fibres than the 

 cathode acts upon in closing. 



Fig. 26. — To illustrate the reason for the increase in the anodal closing 

 stimulation in a muscle after degeneration of the nerve and nerve 

 endings. 



2. Faradic Stimulation. 

 When nerve is stimulated by induced or faradic electricity 



Electric 

 Current. 



Make. 



Break. 



Make. Break. 



Contraction 

 of Muscle. 



Cathode. Anode. 



Galvanic. 



Cathode. Anode. 

 Induced. 



Fig, 27. — To show separation of make and break stimuli and of anodal and 



cathodal effects when a galvanic current is used, and their combina- 

 tion when the induction coil is used {faradic). 



(fig. 28), with each make and break, or with each sudden 

 alteration in the strength of the primary circuit, there is a 

 sudden appearance and equally sudden disappearance of a 

 flow of electricity in the secondary coil. If, therefore, wires 

 from the secondary coil are led ofif to a nerve, each change 

 in the primary circuit causes the sudden and practically 

 simultaneous appearance and disappearance of an electric 



