342 THE OUTGO OF ENERGY 



Within certain narrow limits the height of the 

 contraction will be increased by the increase in 

 the load. With increasing loads the height of 

 contraction diminishes at first quickly, and then 

 more slowly. 



Influence of Temperature on the Form of the 

 Contraction. Prepare a gastrocnemius muscle 

 together with its attachment to the femur. 

 Fasten the femur in the "muscle warmer" (Fig. 

 59). Tie the end of a fine copper wire about 

 ten centimetres long around the Achilles tendon. 

 Bring the wire through the opening in the muscle 

 warmer and fasten the wire around the pulley 

 of the muscle lever. If the pulley is of metal 

 the muscle lever should be supported on a stand 

 separate from that bearing the muscle warmer 

 or should be otherwise insulated. Connect the 

 muscle warmer and the muscle lever with the 

 secondary coil of an inductorium arranged for 

 single induction currents. Fill a beaker with 

 cracked ice and add a little salt. Immerse the 

 muscle warmer in the beaker and support the 

 latter on a suitable stand. Bring the writing 

 point of the muscle lever against a smoked 

 drum. Let the drum revolve at fairly rapid 

 speed. Stimulate the cooling muscle at inter- 

 vals of 5 with a maximal break current. 



