MANUFACTURED COMMERCIAL FERTILIZERS 529 



assumed also that the power company and the works of the Cyanamid Com- 

 pany are so close together that there will be no appreciable loss in electric 

 transmission." 



" Thus the total estimated cost, including interest upon the estimated in- 

 vestment of $444,000, is $45 per metric ton,' equivalent to 22^ cents per 

 kilogram of nitrogen, or 10 cents per pound." 



It should be noted that this 10 cents per pound for cyanamid 

 nitrogen is the estimated cost to the manufacturers, and that it 

 includes no allowance for transportation of the finished product 

 from the factory to the farmer, no allowance for the cost of adver- 

 tising and selling, and no allowance for any profit to anybody. 



It should be noted, too, that the 4 million pounds of combined 

 nitrogen which such a plant could produce in one year would be 

 sufficient, if none were lost in drainage waters, to meet the " grow- 

 ing demands " of the average corn crop of the United States for 

 less than 200 minutes. 



A calcium cyanamid factory is located at Niagara Falls. 



SOURCES OF COMMERCIAL POTASSIUM 



There are three important sources of commercial potassium: 

 (i) the German mines, (2) the salts recovered from the evapora- 

 tion of sea water, and (3) wood ashes. 



Potassium salts of Germany. The very extensive salt deposits 

 in the region of the Harz Mountains in northern Germany con- 

 stitute at present by far the most important source of commercial 

 potassium. These deposits were discovered by borings made near 

 Stassfurt in 1857, and the potassium salts are found chiefly in 

 strata overlying the much thicker stratum of common rock salt. 

 It is estimated that these German salt deposits cover an area of a 

 million acres, and that the supply of potassium which they con- 

 tain is sufficient to supply the present rate of mining for 190,000 

 years. 



It is thought that these salt and potash beds were formed in 

 ancient geologic time by the evaporation of sea water confined in 

 lakes somewhat like the Dead Sea, or Great Salt Lake, except that 

 there. was at times connection with the ocean which supplied the 

 salt water. Evaporation carries off water vapor and leaves the 

 salts in solution, but if the evaporation proceeds far enough, the 



