THE NITROGEN COMPOUNDS 67 



than in other foods, the proportion in grains being the 

 least, and is very small indeed. Such investigations as 

 have been conducted point to the conclusion that amides 

 do not function wholly as do the proteins. This is one 

 reason for regarding the protein of certain vegetable foods 

 as of less value than that of the grains and grain products. 

 86. Extractives. — ^These are bodies found in the extract 

 obtained from beef with cold water. After the albumin 

 has been removed from such an extract by boiling, these 

 compoimds known as creatin and creatinin chiefly con- 

 stitute the nitrogenous solids that .remain. Their food 

 value is small, for they appear to be largely eliminated 

 from the body in the urine without change. 



