Food for salts, all of them readily available. On the other hand, 



he is given little protection in his purchase of Nitrogen. 



2 34 To be sure, the fertilizer laws compel the mixer to state 

 how much Nitrogen there is present in this commodity; 

 yet he is not compelled to tell the exact source or avail- 

 ability of the Nitrogen employed by him. From the 

 consumer's standpoint this is a serious question, since 



Barley. 



Pots manured with Phosphoric Acid, Potash and Nitrate of Soda. 





Nitrate 

 of Soda 



none 



1 gr. 



2gr. 



3gr. 



In agricultural practice from 76 Ibs. to 200 Ibs. of Nitrate of Soda 

 per acre is applied in one or more dressings. 



a pound of Nitrogen costs about four times as much as 

 a pound of either phosphoric acid or potash. If the law 

 required merely the stating of the total per cent, of 

 phosphoric acid or of potash without giving the amount 

 of soluble or available percentages of the same, how 

 incomplete the essential information would be as to the 



