CHAP. X. §.in. DUEING MUSCULAR CONTEA.CTI0N. 131 



of the frogs + IS'SS; after five minutes of con- 

 traction the temperature was increased to + 14". 

 A current was passed fourteen hours after the experi- 

 ment, but neither contractions nor any increase of 

 temperature were observed. 



Tlie results arrived at in the present chapter will 

 lead to the following conclusions. 



First, That during Muscular Contraction, Electricity 

 is evolved. 



Secondly, That during Muscular Contraction, Chemi- 

 cal Action takes place. 



And, thirdly, That during Muscular Contraction, 

 Heat is evolved. 



Matteucci says, " Je pense qu'on doit desormais 

 admettre, comme prouve par 1 'experience, que Taction 

 chimique de . la respiration musculaire pendant la 

 contraction est la cause de la force qui se developpe 

 dans les muscles," 



Now it does not appear to me that we would be 

 justified in considpring one of these circumstances 

 either as a cause or as an effect of the other ; that 

 the chemical action, for instance, should be the cause 

 of the electricity, or vice versa. The muscular fibre 

 during life possesses an electric state, exists in 

 a state of tension, and during contraction this state 

 is lowered, and the force becomes free. This state 

 of tension is again restored by nutrition. Chemical 

 action takes place and heat is evolved at the same 

 time, and together with the evolution of the electric 



