A HARD-WORKING DIET. 44i 



They regarded the theory that " muscular action was 

 brought about by chemical changes alone," as having 

 found such acceptance it might be said to be a 

 universally acknowledged fact. That these chemical 

 changes were processes of oxidation they thought 

 almost equally well established, but the exact point 

 as to what element it was whose oxidation gave 

 origin to muscular power was still a matter of doubt, 

 demanding further experiments. They allude to the 

 recognition that the mechanical work of muscles 

 represented only a part (see p. 367) of the actual 

 energy resulting from the oxidation of the carbon or 

 nitrogen or whatever it was. The limits of the 

 problem narrowed down practically to this was it 

 the oxidation of nitrogen or of carbon which furnished 

 the store of energy? Smith's experiments, referred 

 to above (p. 350), they did not regard as a direct 

 disproof that waste of tissue by the oxidation of 

 nitrogenous matter was the source of power. (Refer- 

 ence to Voit and Bischoff.) They proposed to them- 

 selves direct experiment. Here is their own state- 

 ment, with some few omissions, as rendered in English 

 in the ' Philosophical Magazine.' 



There is one way in which the question whether 

 muscular force can be generated only by the oxida- 

 tion of albuminoid compounds* might be decisively 

 negatived, and that possibly by a single experiment. 

 It is suggested by the following simple line of thought : 

 granting that a person might accomplish a certain 

 measurable amount of external labour, say m metre- 

 kilogrammes, and that in so accomplishing it he 

 oxidized / grammes of albumen in his muscles ; 



* For composition of albumen, see p. 357. 



