Allowance also must be made for phosphoric acid 

 if it is derived from raw bone. It is then worth 

 about 2c. per pound while if taken from steamed 

 bone would be worth fully 5c. per pound. In acidu- 

 lated goods the phosphoric acid is in three different 

 forms, with market values from 2c. up to 5%c. per 

 pound: the water-soluble being worth 5%c. per 

 pound, the insoluble, 2c. per pound. 



The source is just as important a consideration 

 as the quantity when considering the value. Both 

 the quantity of plant food (that is, of nitrogen, 

 phosphoric acid and potash) and its source, which 

 determines its form, are really the only factors which 

 compose the value of a ton of fertilizers. 



Here are two analyses of different total value 

 which will illustrate the foregoing: 



ANALYSIS I. 



Nitrogen in terms of ammonia, 5 % . 

 Equivalent in nitrogen (5X.825) 



4.13 %X20= 82.60 pounds at 16c $13.21 



Phosphoric acid (from steamed bone) 



12X20240 pounds at 5V 2 c 13.20 



Equivalent to bone phosphate 26% 

 Potash (actual, K 2 O) 



3X20=60 pounds at 6c 3.60 



Sulphate of potash, 5.9% 



Total value of ton... $30.01 



20 



