FERTILIZERS 41 



Phosphoric acid\ f /1300 Ibs. bone, 23% 

 15%, 300 Ibs. J lr ^phosphoric acid 299.00 



: 80 Ibs. sulphate 40.00 



COST OF ABOVE MATERIALS. 



1300 Ibs. bone @ $35.00 per ton.. $22.00 



390 " blood @ 50.00 " " 11.70 



80 " sulphate of potash @ 60.00 " " 2.40 



1770 

 230 filler 



2000 Ibs. Total $36.85 



Illustration No. I shows that if the analysis is 

 high, only high grade materials can be used. Illus- 

 tration No. II shows that if the analysis is low, 

 either low grade materials or fillers were used. In No. 

 II, high grade materials up to 1770 Ibs. were used, 

 and their value, pound for pound, is the same as in 

 No. I. A filler used with high grade materials is 

 equivalent to the use of low grade goods and the 

 resulting analysis in No. II shows it. Less blood 

 and bone could have been used in No. II, and more 

 filler, but the resulting analysis would have been 

 still lower. 



63. If, however, the fertilizer is acidulated, the per- 

 centage of plant food may be low, as the weight of 

 acid used displaces some of the material, yet the 

 fertilizer should be considered high grade on account 

 of the more soluble condition of its phosphoric acid. 

 Here, the better form of plant food compensates for 

 the smaller quantity. If the acid phosphate should 

 revert to insolubility on account of the lime or other 

 bases in the soil, its purchase would be equivalent to 

 low grade materials, as the advantage of greater 



