MAINE FERTILIZER CONTROL STATION. 



387 



Timothy hay, XV 



Timothy hay, XXIII 



Clover hay, XXIV 



Clover hay, XXXVII.... 



Oat straw, XXVII 



Oat straw, XXVII ) 

 Potatoes, XXX 5 



Timothy. XXXI1I> 

 Potatoes, XXXII 5 ' *•' 



Corn meal, XX 



Corn-and-cob meal, XXII 



From 100 Parte of Protein in Food, 

 there was Digested 



._ c 

 SS 2 o 



5 1. on 



. c to 

 >» 5. — 



a ® = 





c « 



§ -S M S ® c 



e 





p. OQ 



64.5 



56.6 



52. 



56.2 



45.6 



78.5 



74.4 



82.5 

 82.5 



42.1 

 45.2 

 58.6 

 49.3 

 —8.9 



27.5 



43.9 



86.1 

 75.7 



63.7 

 69.4 

 64.8 

 28.9 



63.8 



70.1 



93.4 

 86.1 



In these comparisons no satisfactory agreement is seen to exist 

 between any two methods. Either the artificial digestion failed to 

 act upon the protein of the food as vigorous!}' as the digestive jSuids 

 in the animal, or the pepsin solution extracted from the feces a portion 

 of the nitrogen belonging to the real undigested food residue. 



Relation of pepsin-soluble nitrogen in feces to the amount of dry 

 substance digested. This has been calculated for each digestion ex- 

 periment, and the results which follow vary widel}' from .400 of a 

 gram of nitrogen to each 100 grams dry substance digested, which 

 is the relation proposed b}' Kellner* for estimating the qiiantit\' of 

 nitrogen in the feces not belono;ing to the undigested food residue. 



*Bied. Centr. Agr. Chemie X, p. 763. 



