164 Fertilizers 



Mixed fertilizers. 



GUARANTEE ON BASIS OP EQUIVALENTS IN COMBINATION 



Nitrogen (equivalent to ammonia) 3 to 4% 



Available phosphoric acid (equivalent to bone phos- 

 phate of lime) 18 to 22% 



Potash (equivalent to sulfate of potash) . . . . 10 to 12% 



GUARANTEE ON BASIS OF ACTUAL CONSTITUENTS 



Nitrogen (total) 2.50 to 3.25% 



Phosphoric acid (available) 8.00 to 10.00% 



Potash (actual) 5.50 to 6.50% 



The guarantees of the raw materials mean practically 

 the same in the first as in the second case. In the first, 

 the percentages given indicate the purity of the chemical 

 salt; while in the second, the figures given indicate the 

 actual content of the constituent contained in the chemical 

 salt. In large commercial transactions, the sales are 

 frequently made on the basis of certain purity percentages ; 

 as, for example, muriate of potash is sold at so much a 

 ton on the basis of 80 per cent muriate. If the analysis 

 shows it to contain less than 80 per cent, then the price 

 paid per ton is less in proportion to such deficiency. 

 If it is shown to contain more than 80 per cent, the pur- 

 chaser pays for the excess at the same rate. In round 

 numbers, a ton of muriate on the 80 per cent basis con- 

 tains 1000 pounds of actual potash; if the price is $40 

 a ton, the cost a pound is 4 cents. If analysis shows but 

 900 pounds instead of 1000, the price paid a ton, at 4 

 cents a pound, is $36. If, on the other hand, it is shown to 

 contain 1110 pounds, the price paid a ton is $44. Pur- 

 chase made when this method of guaranteeing is used is 

 practically equivalent to the "unit" basis, though, as 



