462 



SORGHUM. 



In the following table this is shown, and the results are in every case 

 an average of a very large number of separate analyses, by different 

 chemists often, and of samples of the crop grown in different sections 

 and different years, so that there can be little doubt but that the results 

 are very near the exact truth. 



The aggregate amount of our principal crops is 106,889,390 tons, 

 and the total mineral matter present in this crop equals 3,707,223 tons, 

 and of this mineral matter or ash there are 1,301,224 tons of potash 

 and 679,901 tons of phosphoric acid. In other words, 53.4 per cent 

 of the total mineral matter necessary for the production of our crop 

 of 1879 (and the sa^ie is practically true of every other year) was com- 

 posed of these two constituents, phosphoric acid and potash, which, in 

 commercial fertilizers, agricultural chemists have agreed are worth re- 

 spectively 12 and 7 cents per pound. 



In the matter of fixing these prices, it must be understood that the 

 chemists have no more to do than in fixing the jirice of flour or nails, 

 or any other marketable commodity. They simply declare, from the 

 composition and ])rice of such fertilizing materials as are found in the 

 market, that, in certain forms and in certain markets, these constitu- 

 ents may be obtained at such prices. 



CROPS OF THE UNITED STATES OF AMERICA, 1879. 



In the following table, the value of the potash and phosphoric acid 

 in the several crops has baen calculated, and for the purpose of com- 

 parison the value of the several crops is given : 



