228 AGRICULTURAL CHEMISTRY 



would soon die if its nitrogenous food were entirely in 

 the form of gelatin. Gelatin, when combined with other 

 nutrients, may, however, prevent the rapid conversion of 

 the tissue proteids into circulatory proteids, and thus 

 aids in establishing a proteid equilibrium in the body. 

 Nuclein and some of the nucleated albuminoids have a 

 higher food value than gelatin, and are considered as 

 having the same value as the true proteids. As a 

 nutrient, the gelatin albuminoids conserve the proteids 

 of the body, but do not take the place of proteids in the 

 repair of worn-out tissues. 



Amides and Amines 



314. Composition and Properties. The amides and 

 amines are heterogeneous compounds found in both 

 animal and plant bodies. They are less complex in com- 

 position than either the proteids or albuminoids ; and are 

 produced by replacing one or more of the hydrogen atoms 

 of ammonia with an organic radical. If the radical is 

 acid in character, an amide is formed ; if alcoholic or 

 basic, an amine is produced. Amides and amines are re- 

 lated to ammonia as will be observed from the following 

 formulas : 



/H /C.H.O, /CH, 



N H N H N H 



\H \H \H 



Ammonia. Amide. Amine. 



( Amidoacetic acid. ) ( Methylamine. ) 



When the methyl group or radical replaces one of the 

 hydrogen atoms of NH 3 , the product is methylamine. 

 When the acetic acid radical replaces one of the hydrogen 



