THE CHANGE IN FORM 341 



muscle clamp with the secondary coil of the in- 

 ductorium. Bring the writing point against the 

 smoked drum. Stimulate the muscle with break 

 induction currents of varying intensity and record 

 the contraction curves. 



It will be found that the contraction is longer 

 with weak stimuli than with strong. 



Influence of Load on Height of Contraction. 

 Attach a curarized gastrocnemius preparation 

 to the muscle lever and bring the writing point 

 against a smoked drum. Connect the binding 

 posts on the lever and the muscle clamp with 

 the secondary coil of the inductorium. Load 

 the muscle with the lever and scale-pan only. 

 With the drum at rest record the contraction 

 on stimulation with a maximal induction current. 

 Turn. the drum by hand one millimetre. Place 

 a one-gram weight in the scale-pan, and record 

 the contraction produced by a make induction 

 current of the same intensity as before. Con- 

 tinue to add gram weights and to record the 

 contractions until ten one-gram weights have 

 been placed in the scale-pan. Now increase the 

 load each time by ten grams, recording the con- 

 traction after each increase, until the muscle is 

 weighted with one hundred grams. (Care should 

 be taken not to fatigue the muscle by stimulating 

 it oftener than is necessary to obtain the record.) 



