MANUAL OF CATTLE-FJEEDING. 213 



haustion may do so. This conclusion appears to be in 

 liarmony with Kellner's results. 



§ 2. The Souece op Musculah Power. 



Thus far we have simply been considering expeiimental 

 results, without regard to the conclusions to be diawn 

 from them. "We now come to their interpretation, and 

 here it must be admitted, at the outset, that the knowledge 

 as yet gained is insufficient to enable us to state with cer- 

 tainty the source of nmscular power. 



Any elaborate discussion of the question would be out 

 of place here, and we shall simply endeavor to present 

 sonae general considerations bearing on this point, and to 

 indicate what seem, in the present state of our knowledge, 

 to be the most probable conclusions. 



Increased Oxidation of Source of Power not ne- 

 cessary. — At iirst thought the results detailed in the pre- 

 ceding section seem to plainly indicate the non-nitroge- 

 nous ingredients of the body as the source of muscular 

 power, since these nndorgo an increased oxidation during 

 work, wliile the protein docs bo at most only to a .mall ex- 

 tent, if at all ; and in fact many eminent physiologistb hold 

 that it is the decomposition of these bodies which supplies 

 the energy for the production of work. 



But this is by no means a necessary conclusion. We 

 must distinguish between the source and the consecjuence 

 of muscular exertion. The continual decomposition of 

 matter which goes on in the living body must bo accom- 

 panied by the liberation of a corresponding amount o£ 

 force. Part of this force is set free as heat, part probably 

 as electricity, continual currents of which circulate in the 

 liung muscle. Now it is quite conceivable that, in mus- 



