10 



The above table shows that of the 31 manufacturers, 27 showed an overrun in 

 all three elements; 30 showed an overrun and 1 a shortage in nitrogen; 28 showed 

 an overrun and 3 a shortage in potash; and all showed an overrun m available 

 phosphoric acid. The average margin allowed for nitrogen was naturally lower 

 than for the other two elements on account of its greater cost, yet in this element a 

 great improvement is noted over 1924 when 8 out of 32 manufacturers showed a 

 shortage. The table shows that as a general rule proper allowances are made for 

 marginal overruns. 



Nitrogen in Mixed Fertilizers. 



The following table records the average proportion of mineral and organic 

 nitrogen used in mixed fertilizers, as well as the activity of the organic forms. For 

 this study the fertilizers have been divided into groups according to the minimum 

 ammonia guarantee, each succeeding group representing an increase of one per cent 

 in ammonia. An average of all the mixed fertilizers analyzed showed: total 

 nitrogen, 3.87 per cent; nitrogen from mineral forms, 2.07 per cent; from organic 

 sources, 1.80 per cent. The activity of the total organic nitrogen was 77 per cent, 

 and of the water insoluble nitrogen, 65.5 per cent, the alkaline permanganate 

 method being used on all brands except the tobacco goods which carried a consider- 

 able proportion of organic vegetable ammoniates. 



