136 APPENDIX II. 



their restoration. . . . All these facts prove that 

 transformation of the muscle through the agency of 

 oxygen is the condition of muscular action." 

 Finally, in a masterly review of the present re- 

 lations of chemistry to animal life, published in 

 March last, * Odling says, page 98 : " Seeing, then, 

 that muscular exertion is really dependent upon 

 muscular oxidation, we have to consider what should 

 be the products, and what the value of this oxida- 

 tion." And again, page 103 : " The slow oxida- 

 tion of so much carbon and hydrogen in the 

 human body, therefore, will always produce its due 

 amount of heat, or an equivalent in some other form 

 of energy ; for while the latent force liberated by 

 the combustion of the carbon and hydrogen of fat is 

 expressed solely in the form of heat, the combustion 

 of an equal quantity of the carbon and hydrogen of 

 voluntary muscle is expressed chiefly in the form of 

 motion" 



Nevertheless, this view of the origin of muscular 

 power has not escaped challenge. Immediately 

 after its first promulgation, Dr. J. K. Mayer wrote :f 

 " A muscle is only an apparatus by means of which 

 the transformation of force is effected, but it is not the 

 material by the chemical change of which mechanical 

 work is produced." He showed that the 15 Ibs. of 

 dry muscles of a man weighing 150 Ibs. would, if 

 their mechanical work were due to their chemical 

 change, be completely oxidized in 80 days, the heart 



* Lectures on Animal Chemistry. 



t Die organische Bewegung in ihrem Zusammenhange mil 

 dem Sto/wechsel, 1845. 



