IV 



ELECTROMOTIVE ACTION IN MUSCLE 



369 



circuit repeats itself, and if the process of negative closure has 

 run out during this period, no deflection will be obtained. On 

 actually working the experiment, however, we still find a 

 negative deflection increasing slowly throughout the entire period 

 of excitation, i.e. in the direction of the compensating current, due 

 apparently to the diminutional after-effect of excitation upon the 

 muscle current as described. Now, if the exciting slider is 

 brought more forward, so that excitation occurs while the 

 galvanometer contacts are still dipping into mercury, we find 



FIG. 110 Schema of rheotome experiment. (Bernstein.) 



at a particular point a sudden increment in the deflection, which 

 increases rapidly in the negative direction on pushing on the 

 slider, and finally reaches a maximum, after which it decreases 

 again with further displacement of the slider, and at last remains 

 persistently lower than it was at the beginning of the excitation. 

 This shows that there is a measurable interval between the 

 moment of excitation at one point of a muscle with parallel 

 fibres (Bernstein always chooses the lower end of the sartorius 

 as being free from nerves), and the beginning of the negative 

 variation at the other, provided with an artificial cross-section ; 



2 B 



