312 Bureau of Farmers' Institutes. 



Rules for Making Valuations of Unmixed Fertilizing 



Materials. 



(a) Materials Containing Nitrogen. 



(1) Sulphate of Ammonia. Rule. Multiply the given per cent, 

 of ammonia by 0.82 and tJbis product by the price of one 'pound of 

 nitrogen in the form of ammonia (see price list on page 309). 

 Multiply this product by 20. 



Example. — A sample of ammonium sulphate tests 24 per cent, 

 ammonia; what is its commercial valuation? 



24 per cent, of ammonia) x 0.82 = 19.68 per cent, of nitrogen. 



19.68 x 15 cents = 295 cents, value of nitrogen in 100 pounds 

 of ammonium sulphate. 



295 cents x 20 = $59, value of nitrogen in one ton of am- 

 monium sulphate. 



(2) Nitrate of Soda. Rule. Multiply the test per cent, of 

 nitrate of soda by 16^ and this product by the price of one pound 

 of nitrogen in the form of nitrates (see price list on page 309). 

 Multiply the last result by 20. 



Example. — What is the valuation of one ton of nitrate of soda 

 which tests 98 per cent.? 



" Nitrate of soda testing 98 per cent." means that in every 100 

 pounds of material there are 98 pounds of pure nitrate of soda. 



98x0.165 = 16.17 per cent, nitrogen in nitrate of soda. 



16.17 x 121 cents = 202 cents x 20 = $40.40 a ton. 



When the per cent, of nitrogen is given, then the first step is 

 omitted. 



(b) Materials Containing Phosphoric Acid. 



(1) Available Guaranteed. Rule. Multiply the given amount 

 of available phosphoric acid by the price of one pound of soluble 

 phosphoric acid (sec price list on page 309) and the result by 20. 



If the amount of insoluble phosphoric acid is given, multiply 

 this by 40 and add to foregoing amount. 



Example: What is the commercial valuation of one ton of 

 dissolved hone black testing 16 per cent, of available phosphoric 

 acid? 



16 x 4| cents = 72 cents x 20 = $14.40 a ton. 



If this sample were known also to contain two per cent, of in- 

 soluble phosphoric acid, then 



2x40 cents = 80 cents and $14.40 + 0.80 = $15.20. 



