ALTERATION IN MUSCLE-FORCE DURING CONTRACTION. 7 1 



more rapidly. The muscle having contracted as far as 

 possible without any weight, it can naturally no longer 

 raise any weight — its whole energy is expended. 



The interest of this experiment lies in the fact that 

 it shows in a different way that which we have already 

 said (p. 48) as to change in elasticity during contraction. 

 For these experiments determine the weight proper to 

 each length of the active muscle, so that we can also 

 directly deduce from these the curves of extension of 

 an active muscle, which we had previously constructed 

 only theoretically. The agreement of this deduction 

 with the theory, found in a different way, is an impor- 

 tant confirmation of the views which we have developed 

 as to the bearing of the conditions of elasticity on the 

 labour accomplished by the muscle. 



