MANURES AND FERTILIZING MATERIALS. 67 



SECTION XIII. VALUATION OF FERTILIZERS. 



Vcs* >> 



Meaning of the Guarantee. Nitrate of soda, 

 kainit, cotton-seed meal, acid phosphate, etc., are sold 

 either unmixed or mixed. When any two fertilizers 

 are mixed they are called mixed or manufactured fer- 

 tilizers. In order to protect the purchasers, most 

 states have passed laws which require that the manu- 

 facturer shall state the amounts of phosphoric acid, 

 nitrogen and potash which his fertilizers contain. 

 This statement is called the guarantee. The guaran- 

 tee is printed either on the sack or on tags which are 



IOOLBS 



CORN FERTILIZER. 



MANUFACTURED BY 



JOHN BflOWN 



MEMPHIS, TENN 



/IVJIL/IBLE PHOSPHORIC4CID '1 1.00 "1. 



NlTftOGEN 1.65 



AMMONIA .00 



POTASH E. 00 



A TAG WITH THE GUARANTEE OR SAMPLE OF COMMERCIAL 

 FERTILIZER TAG. 



attached to the sacks. The weight of the contents of 

 each sack is required by many states. Supposing a 

 fertilizer is guaranteed 8 per cent, available phos- 

 phoric acid, 1.65 per cent, nitrogen and 2 per cent, pot- 

 ash; it means that in every 100 Ibs. of this fertilizer 

 there are at least 8 Ibs. of available phosphoric acid, 

 1.65 Ibs. of nitrogen and 2 Ibs. of potash. 



Valuation of Fertilizers. The commercial value of 

 a fertilizer depends upon the market prices of the in- 

 gredients nitrogen, phosphoric acid and potash. In 

 most of the states the chemist charged with the en- 

 forcement of fertilizer laws, ascertains the average 

 market values of the materials which furnish nitrogen, 



