CHAPTER XXIV 

 Nitrogenous Organic Compounds of Plants 



291. Amount of Nitrogenous Matter in Plants. 



As a rule, less than 15 per cent, of the dry matter of 

 plants is nitrogenous material. In the seeds of legumes, 

 as beans and peas, this amounts to about 22 per cent. In 

 nearly all plants, the non-nitrogenous compounds are 

 from six to ten times more abundant than the nitrogenous. 



292. Different Terms Applied to Nitrogenous Com- 

 pounds. Unfortunately, the various terms used to desig- 

 nate the nitrogenous compounds have not been uniformly 

 applied. The terms nitrogenous compounds, proteids, 

 crude protein, and albuminoids have been used synony- 

 mously, but each applies to a different class of bodies. 

 The terms organic nitrogenous compounds and crude 

 protein are the most satisfactory when applied to the 

 entire group ; proteids and albuminoids are subdivisions 

 of the nitrogenous compounds. 



293. Complexity of Composition. The nitrogenous 

 compounds are more complex in composition than the 

 non-nitrogenous. The percentage composition and for- 

 mulas of nearly all of the non-nitrogenous compounds of 

 plants have been determined, and while the percentage 

 composition and the physical and chemical properties of 

 the more important nitrogenous compounds are known 

 no definite formulas have, as 3 T et, been applied because of 

 the complexity of their molecular structure. The nitroge- 



