PRODUCTS OF DISASSIMILATION. 393 



of the process of nutrition. We shall not discuss here the 

 influence of work upon the elimination of some of the nitro- 

 genized compounds, particularly urea, for we have already 

 examined that subject most carefully in another place ; x but 

 we have no hesitation in stating, as a general law, that has 

 yet to find its exceptions, that physiological work increases 

 excretion. 



1 See page 226. 



