The call for oxygen by muscle 



79 



and the delayed heat-production occurs in recovery processes : and 

 that these processes cannot occur in the absence of oxygen. He 

 argued moreover that his results were in favour, neither of the 

 hypothesis of intra-molecular oxygen, nor of the idea that oxygen is 

 used as required in the simple processes of energy liberation. He 

 suggested in fact that his results were in favour of the old view that 

 oxygen is used largely in the processes whereby the molecular 



30 



FIG. 42. Galvanometer deflection for rise of temperature of muscle excited in nitrogen, 

 and later in oxygen, and finally warmed when dead (control). Note that the curve of the 

 deflection for the live muscle in nitrogen very nearly coincides with the control curve, 

 and that the curve for the live muscle placed in oxygen after nitrogen is considerably 

 displaced to the right. 



machine like a steam-engine charging an accumulator builds up 

 bodies containing considerable amounts of potential energy which 

 (like the accumulator) can be discharged whenever desired on sub- 

 jecting the tissues to appropriate stimuli : that oxygen is used in 

 maintaining the activity, the state of potential energy, of the 

 organism, and is therefore largely used after activity has occurred 

 in * preparation for the next period of activity*. 



The construction which is to be put on these experiments is that 

 * I am indebted to Hill for the above statement of his results. 



