TOBACCO CCTLTUKE. 75 



not attempt to ascertain and state in which iorm 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 present without regard to the particular form or 

 forms in which it is present. 



(H) Ammonia consists of nitrogen combined with hy- 

 drogen. 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 neces- 

 sary amount of hydrogen added to form ammonia. The 

 chemical relations of nitrogen and ammonia are such that 

 14 pounds of nitrogen will unite with exactly 3 pounds of 

 hydrogen, and will, therefore, produce just 17 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 un- 

 common in commercial fertilizers, because nitrogen in this 

 form is the most expensive and, therefore, least used. Strict- 

 ly speaking, the term ammonia should never be used except 

 when sulphate of ammonia or some similar compound is 

 present in the fertilizer. 



