44 FERTILIZERS 



Water 16.0 (combined with organic 



matter and sulphuric acid) 



Nitrogen 2.0 



Phosphoric acid 10.6 



Potash 2.9 



Volatile and organic 33.0 (Combined with nitrogen) 



Gypsum 16.0 (Formed by action of 



sulphuric acid on rock.) 



Lime 7.1 (Left combined with phos- 

 phoric acid) 



Sand 4.0 (Impurity prosp. rock.) 



Chlorine and Salts.. 3.0 (Combined with potash.) 



Miscellaneous 5.2 



100.0 



Of the ten substances which compose the above 

 100 per cent, only three are of interest to the farmer. 

 The value of the whole ton is based on the value of 

 the nitrogen, phosphoric acid, and potash, only. 



In raw bone, for example, it is impossible to give 

 a farmer the 3% nitrogen and the 24-% phosphoric 

 acid contained without giving him the 73% of lime, 

 gelatines and fats, etc., found in bone, for these sub- 

 stances are in combination and the process of separ- 

 ation would be too costly. 



HOW TO UNDERSTAND A FERTILIZER ANALYSIS 



66. Manufacturers often state the analysis of their 

 fertilizers in a confusing way. They use two terms 

 to express the same thing. Nitrogen and ammonia 

 both mean one thing, and the analysis should read, 

 for example, "nitrogen 4.95% equal to ammonia 

 6%," showing that there is not both the 4.95%, and 

 the 6%, but only one or the other. That the one 

 repeats the other. Multiply the percentage of am- 

 monia by .825 and the result will be the equivalent 



