220 THE POTATO 



County. Such a mixture can be made from the 

 following materials, using the same grade as in the 

 4-6-10 mixture given above: 



200 pounds nitrate soda. 

 980 tankage, 



400 " acid phosphate. 

 280 " sulphate potash. 



1860 pounds (equivalent to a ton). 



Cost f.o.b. Boston, $28.15. Cost of mixing, same 

 as before. Freight extra. " 



