32 THE PHYSIOLOGY OF MUSCLE AND NERVE. 



sometimes shows also a double contraction for a single stimulus. 

 The very prolonged relaxation is, however, the most peculiar effect 



Fig. 15. Effect of repeated stimulation; complete curve, showing late contracture. 

 The muscle was stimulated by induction shocks at the rate of 50 per minute. The separate 

 contractions are so close together that they can not be distinguished. 



of the veratrin. A somewhat similar effect is produced by the 

 action of glycerin. We have in such substances reagents that affect 

 one phase of the contraction process without materially influencing 

 the other. As regards the veratrin effect, it becomes less and less 



Fig. 16. Effect of repeated stimulation, curve showing no contracture or very little. 

 "The muscle was stimulated by induction shocks at the rate of 50 per minute. A very 

 slight contracture is shown in the beginning, but subsequently the contractions show 

 only a diminished extent, the rate of relaxation remaining apparently unchanged. 



marked if the muscle is made to give repeated contractions, but 

 reappears after a suitable period of rest. The peculiar action of 

 the veratrin is therefore antagonized seemingly by the chemical 

 products formed during contraction. 



