166 



APPENDIX II. 



The following are the results expressed as in the 

 previous cases : 



Hard-worked Labourer. (Playfair.) 



Thus, even under the extremely unfavourable con- 

 ditions of these determinations, the actual work 

 performed exceeded that which could possibly be 

 produced through the oxidation of the nitrogenous 

 constituents of the daily food by more than 30 per 

 cent. 



9thly. We have seen, therefore, in the above four 

 sets of experiments, interpreted by the data afforded 

 by the combustion of muscle and urea in oxygen, that 

 the transformation of tissue alone cannot account for 

 more than a small fraction of the muscular power 

 developed by animals; in fact, this transformation 

 goes on at a rate almost entirely independent of the 

 amount of muscular power developed. If the me- 

 chanical work of an animal be doubled or trebled 

 there is no corresponding increase of nitrogen in 

 the secretions ; whilst it was proved on the other 

 hand by Lawes and Gilbert, as early as the year 

 1854, that animals, under the same conditions as re- 



