COTTON CULTURE 77 



does not attempt to ascertain and state in which form or 

 forms the nitrogen is present in a fertilizer. 



When, therefore, nitrogen is expressed in an analysis 

 or guarantee as "ammonia," it refers to the entire amount 

 of nitrogen, without regard to the particular form or forms 

 in which it is present. 



(6) Ammonia consists of nitrogen combined with hydro- 

 gen. A pound of nitrogen will form more than a pound 

 of ammonia, because the ammonia formed from a pound 

 of nitrogen will contain that pound of nitrogen plus the 

 necessary amount of hydrogen added to form ammonia. 

 The chemical relations of nitrogen and ammonia are such 

 that fourteen pounds of nitrogen will unite with exactly 

 three pounds of hydrogen, and will, therefore, produce 

 seventeen pounds of ammonia; or one pound of nitrogen 

 will make 1.214 pounds of ammonia. 



(c) Nitrogen equal (or equivalent) to Ammonia is a form 

 of expression which simply means that the nitrogen is 

 stated not as nitrogen but as ammonia. 



It would be better on every account if all guarantees 

 stated simply nitrogen and never mentioned ammonia at 

 all. As a matter of fact, compounds of ammonia are quite 

 uncommon in commercial fertilizers, because nitrogen in 

 this form is the most expensive and, therefore, least used. 

 Strictly speaking, the term ammonia should never be used 

 except when sulfate of ammonia or some similar com- 

 pound is present in the fertilizer. 



The following table gives the composition of the most 

 commonly known fertilizer materials: 



