88 PRACTICAL FARM CHEMISTRY. 



$30.20 worth of raw materials. On tlie basis of 

 the higher figures, we find in each 100 pounds: 



4 pounds nitrogen @ 18^ cent?, ... 74 



8 " soluble phosphoric acid @, 8 cents, - - 64 



8 " insoluble " " @ 3 cents, - 6 



10 " potash @, 5i cents, - - - - 55 



/ Total, $1.99 



/ or in one ton (2000 pounds) 20 times $1.89, or $39.80. 

 Thus we see that the value of the raw materials in 

 such high-grade fertilizer may vary between $30.20 

 and $39.80. The goods of our reputable fertilizer 

 firms usually come near the higher figure, and in 

 many cases they go even above it. Add to this the 

 various expenses of manufacturing and selling, and 

 the price of a fertilizer with guaranteed analyses as 

 the one in consideration can hardly be expected to 

 be much below forty dollars per ton. 



If we examine a fertilizer on the packages of 

 which we find guaranteed analyses as follows, viz: 



Nitrogen, - - - - 1 to 2 per cent. 



Available phosphoric acid, - - 6 to 8 " •' 



Insoluble " " - - 2 to 3 " '* 



Total, - - - - - 8 to 10 " " 



Potash, - - - - 2to 4 " " 



we may make the following estimate of its chemical 

 value (value of the raw materials of plant food at 

 retail) per 100 pounds, viz.: 



/. Based on lower figures of analyses: 



Nitrogen, 1 pound @ 18^ cents, . - - 18^ 



Phosphoric acid, available 6 pounds @ 8 cents, - 48 



* ' " insoluble 2 pounds @, 2 cents, - 4 



Potash (probably muriate) 2 pounds @ 4i cents, 9 



Total, 79i^ 



or per ton, 20x79 J cts. equal to $15.90. The valuation 

 on this basis would perhaps not be fair to the 



