2IO 



NUTRITION OF FARM ANIMALS 



water contained in the air of the apparatus shows the amounts 

 of these substances produced, while the amount of fresh oxygen 

 admitted minus any increase of the oxygen contained in the air 

 of the apparatus shows the quantity of this element absorbed. 



u 



Any methane or hydrogen excreted accumulates in the ap- 

 paratus and may be determined by an analysis of the contained 

 air at the close of the experiment. The amount of nitrogen 

 contained in the apparatus should, of course, remain unchanged 

 if the apparatus is working properly. 



