assumed that the organic nitrogen is derived from the best sources, 

 viz. : bone, blood, animal matter, or other equally good forms and 

 not from leather, shoddy, hair or any low-priced inferior form of 

 vegetable matter, unless the contrary is ascertained. 



Insoluble Phosphoric acid will be valued at 3 cents, it being 

 assumed, unless found otherwise, that it is from bone or similar 

 source and not from rock phosphate. In this latter form the insol- 

 uble phosphoric acid is worth but 2 cents per pound. Potash is 

 rated at 4^ cents, if sufficient chlorine is present in the fertilizer to 

 combine with it to make muriate. If there is more Potash present 

 than will combine with the chlorine, then this excess of Potash will 

 be counted as sulphate. To introduce large quantities of chlorides, 

 common salt, etc., into fertilizer, claiming sulphate of potash as a 

 constituent, is a practice, which in our present state of information 

 will be considered of doubtful merit. The use of the highest trade 

 values is but justice to these articles in which the costliest materials 

 are exjiected to be used. 



In most cases the valuation of the ingredients in Superphosphates 

 and Specials falls below the retail price of these goods. The differ- 

 ence between the two figures, represents the manufacturer's charges 

 for converting raw materials into manufactured articles. These 

 charges are for grinding and mixing, bagging or barreling, storage 

 and transportation, commission to agents, and dealers, long credits, 

 interest on investment, bad debts, and finally profits. 



The prices stated in these bulletins in connection with analyses of 

 commercial fertilizers refer to their cost per ton of 2,000 pounds, on 

 board of car or boat near the factory, or place for general distribu- 

 tion. To obtain the Valuation of a Fertilizer (i. e. the money-worth 

 of its fertilizing ingredients), we multiply the pounds per ton of 

 Nitrogen, etc., by the trade-value per pound. We thus get the values 

 per ton of the several ingredients, and adding them together we 

 obtain the total valuation per ton. 



The mechanical condition of any fertilizing material, simple or 

 compound, deserves the most serious consideration of farmers, when 

 articles of a similar chemical character are offered for their choice. 

 The degree of pulverization controls, almost without exception, under 

 similar conditions, the rate of solubility, and the more or less rapid 

 diffusion of the tlifferent articles of plant-food throughout the soil. 



The state of moisture exerts a no less important influence on the 

 pecuniary value, in case of one and the same kind of substance. 



