29 



Phosphoric Acid in Complete Fertilizers. Eighty-six and three- ' 

 tenths per cent of the total phosphoric acid found in all the complete 



fertilizers was present in available form, and 50.4 per cent of the avail- \ 



able phosphoric acid was present in water soluble form. This shows • 



a satisfactory availability, and indicates the use of high grade sources t 



of phosphoric acid in the mixed complete fertilizers. j 



Phosphoric Acid in Amnioniated Superphosphates. Eighty-five I 



per cent of the total phosphoric acid found in all the ammoiiiated i 



superphosphates was present in available form, and 52 per cent 

 of the available phosphoric acid was present in water soluble form. , 



In other words, the forms were but little different from those found 

 in mixed complete goods. * 



j 



Potash. The average complete fertilizer showed the presence • 



of 1.34 per cent of water soluble potash. Most of the brands were ^ 



guaranteed only 1 per cent, although some tobacco brands were J 



guaranteed 2 per cent. In all probability most of the potash used • 



M'as in form of sulfate, or from grades of domestic potash salt con- ' 



taining both muriate and sulfate. Very little German potash salt 

 has been imported (during the year. Potash has been offered to the 

 trade from several sources, among them being kelp potash, potash 

 from evaporation of water of saline lakes in the west, sulfate of pot- 

 ash from Alunite, and a potash salt from Japan containing both sul- 

 fate and muriate. 



Out of a total of 226 brands, 70 (31 per cent) had the major 

 portion of their potash in form of sulfate. In the other brands a 

 sufficient amount of chlorine was present to satisfy all of the potash. 

 This does not necessarily meanthatthe source of potash was muriate, 

 as thissalthas been valued from $100 to $150 per ton more than the 

 sulfate, on account of its great demand in the chemical industry. 

 It is probable that in cases where considerable amounts of chlorine 

 were present, grades of potash were used that had both sulfates and 

 chlorides, which would lessen their value for other industrial purposes. 



Twenty-six brands of tobacco fertilizer have been examined. 

 The average total water soluble potash found was 1.38 per cent, 

 of which .94 per cent was from sulfate and .44 per cent from muriate. 

 The potash in mixed goods has cost the consumer, during the past 

 season, $5.00 per unit, or 25 cents per pound. In the tables of analy- 

 ses wherever potash has been found present as sulfate, an asterisk 

 has been used in the "found" potash column, and foot notes desig- 

 nate the proportion of each form present. 



