56 EXPERIMENTAL PHYSIOLOGY 



ing and (2) in a descending direction, and determine the effect 

 of its poles in diminishing or increasing the excitability of the nerve 

 as tested by the height of the ordinates described by the myograph 

 lever. 



This experiment can be performed without taking a graphic record by noting 

 at what distance the secondary coil must be placed in order just to produce a 

 contraction. In this way the varying conditions of excitability produced by 

 the polarising current are tested and may be recorded numerically. 



