AGRICULTURAL EXPERIMENT STATION. 



285 



too small, in fact, to entitle it to serious consideration. Of the 

 nitrogen compounds extracted by method B, we have no knowl- 

 edge of any likely to be present, outside of the albuminoids, pep- 

 tones and amides, that can properly be classed with the undigested 

 residue. The observations so far made all point to the conclusion, 

 that nearly all the nitrogen extracted by this method belongs to 

 the biliary and other waste products which are only incidentally 

 present in the fseces. 



A comparison of the digestion coefficients of protein as found 

 in the ordinary manner, after correction by method B, and by the 

 artificial pepsin pancreas digestion, is made below : 



Coefflcieuts of digestibility of protein. 



Hays, Fodders and Ensilage. 



Timothy Hay early-cut. 



'• late-cut.. 



Wild Oat Grass Hay.... 



Red Top Hay 



Blue Joint Hay 



Witch Grass Hay 



Alsike Clover Hay 



South Corn Fodder 



Field Corn Fodder 



Sweet Corn Fodder 



South Corn Ensilage. . 



Field Corn Ensilage 



Sweet Corn Ensilage. . 



By usual 



method with 



animals. 



Usual method 



with animals 



corrected by 



Method B. 



58.9 



oO. 



GS. 



62.2 



70.2 



52.9 



68.2 



58.1 



63.6 



59. 



46.6 



52.8 



54.1 



By pepsin- 

 pancreas di- 

 gestion. 



58.8 69.8 72.3 



These results are strikingly similar to those obtained in 1888, 

 when the coefficients found by the use of method B were ten and 

 four-teutlis per cent, higher than where the correction was not 

 applied, and here we see the difference is eleven per cent. More- 

 over the method with animals after applying the correction agrees 

 in both instances very closely with the results obtained by the use 

 of artificial pepsin and pancreas solutions. 



It is a question whether we can any longer afford to ignore this 

 difference of ten per cent., which must be wholly or in very large 

 part due to compounds that do not properly belong to the undi- 

 gested residue. The fact that the error introduced in this way 

 affects the apparent digestibility of protein in hays and other 

 coarse fodders much moi'e than in the case of concentrated nitro- 

 genous foods is a strong argument for applying a correction when- 

 ever we are reasonably sure that we have arrived at one that is 

 fairly accurate. 



