goods. Occasionally a sample is found guaranteed in the ammonia 

 equivalent ; this is not legal according to Massachusetts laws. 

 Ammonia may be guaranteed in conjunction with, but never in place 

 of, the nitrogen. The consumer should always insist upon a nitro- 

 gen guarantee and any case where ammonia is stated in place of 

 nitrogen, should be called to the attention of the experiment 

 station authorities. 



Some manufacturers have adopted the unfortunate practice of 

 so wording their potash guarantee as to lead the unwary to assume 

 that the potash is present in form of sulphate when, in reality, it is 

 present in the cheaper form of chloride or muriate. A common 

 practice among manufacturers is to guarantee the percentage 

 of actual potash, and on the line below, to print the words " equiva- 

 lent to sulphate of potash," giving in computed tigures the equiva- 

 lent of this compound. The close observer will find that when a 

 fertilizer manufacturer wishes to advertise the fact that he is using 

 high grade sulphate of potash in any particular brand of fertilizer 

 he will say ^"^ In form of sulphate of potash. "' and not "Equivalent to 

 sulphate of potash." 



The usual practice is to guarantee a minimum and maximum 

 amount of the various essential elements of plant food. These 

 guarantees often vary widely, as potash from 2 to 4 per cent and 

 phosphoric acid from 8 to 12 per cent. It should be borne in mind 

 that only the lower hgure is binding, and that the manufacturer 

 has fulfilled his contract in furnishing the minimum amount of plant 

 food guaranteed. 



The following tables show the comparative quality of the brands 

 of complete fertilizers and crude stock materials such as bones, tank- 

 age and dry ground fish. 



