50 CHEMICAL FERTILIZERS; AND LIME 



Multiplying the lowest figure representing the per cent of the given 

 element by 20, and calculating the value from the price per pound, we 

 have in No. 1 (remembering that 1 per cent means one pound in a 

 hundred, or twenty pounds in a ton) : 



Nitrogen 1.60 X 20 = 32 Ib. 150 = $4.80 



Phosphoric acid 7 X 20 = 140 Ib. @ 50 = 7.00 



Potash 2 X 20 = 40 Ib. @ 5? = 2.00 



Commercial value per ton $13.80 



EXAMPLE No. 2. GUARANTEED ANALYSIS 



Nitrogen 3.30 to 4.00 per cent 



Phosphoric acid available 8.00 to 10.00 per cent 



Potash 7.00 to 8.00 per cent 



Cost per ton $38.00 



Its value is calculated the same as No. 1 : - 



Nitrogen 3.30 X 20 = 66 Ib. 150 = $9.90 



Phosphoric acid 8.00 X 20 = 160 Ib. @ 50 = 8.00 



Potash 7.00 X 20 = 140 Ib. @ 50 = 7.00 



Commercial value $24.90 



The cheapest fertilizer is the one in which one dollar purchases the 

 greatest amount of plant-food. In No. 1, $29 obtained $13.80 worth, 

 which is at the rate of forty-eight cents worth for $L In No. 2, $38 

 buys $24.90 worth of plant-food, or at the rate of sixty-five cents worth 

 for the dollar. The difference between the commercial value, as calcu- 

 lated, and the selling price, is to cover expenses of manufacture, bag- 

 ging, shipping, commission fees, and profits. 



How to figure the trade value of a fertilizer in greater detail ( Voorhees) 

 It is assumed that the mixed fertilizer is guaranteed to contain 



Ammonia 4 per cent 



Available phosphoric acid 8 per cent 



Total phosphoric acid 9 per cent 



Potash 6 per cent 



and that the nitrogen exists in three forms, as nitrate, as ammonia, and 

 as organic ; the phosphoric acid in three forms, soluble, reverted, and 

 insoluble ; and potash in two forms, sulfate and muriate. The 4 per 

 cent ammonia would be equivalent to 3.28 per cent nitrogen, 1 per cent 

 of which is nitrate-nitrogen, $ per cent sulfate -of ammonia-nitrogen, 



