170 



CHEMISTRY OF FARM PRACTICE 



phoric anhydride and 8 per cent water-soluble potash); 

 but due to the increased weight, the per cent is corre- 

 spondingly diminished. 



The results are tabulated as follows: 



Therefore the number of pounds to be applied that will 

 contain the same amount of plant food as 1000 pounds of a 

 5-8-8 fertilizer can be calculated by making use of the follow- 

 ing proportion: 



2000 : 2047 = 1000 : a; = 1024 pounds. 



(4) Given, high-grade materials; make to the proportion 

 of a low-grade formula, and avoid the use of a filler. 



PROBLEM: Calculate a formula analyzing nitrogen 

 equivalent to 3 per cent of ammonia, 8 per cent of available 

 phosphoric acid, and 3 per cent of water-soluble potash, 

 one-third of the nitrogen to be derived from sulphate of 

 ammonia, which contains 24 per cent of ammonia, and 

 two-thirds from cottonseed meal; the phosphoric anhydride, 

 from 16 per cent acid phosphate; and the potash, from 48 

 per cent muriate of potash. Calculate the analysis of the 

 formula if no filler is added, and the number of pounds of 

 this mixture equivalent to 500 pounds of a " 3-8-3 " fer- 

 tilizer. 



