13 



existing circumstances and special wants. In some cases it may be 

 mainly either phosphoric acid or nitrogen or potash, in others, two of 

 them, and in others again, all three. 



A remunerative use of commercial fertilizers can only be secured 

 by attending carefully to the above stated considerations. 



To assist farmers not yet familiar with the current mode of deter- 

 mining the commercial value of manurial substances offered for sale 

 in our markets, some of the essential considerations, which serve as 

 a basis for their commercial valuation, are once more stated within a 

 few subsequent pages. 



The hitherto customary valuation of manurial substances is based 

 on the average trade value of the essential fertilizing elements si)eci- 

 fied by analysis. The money value of the higher grades of agricul- 

 tural chemicals and of the higher priced compound fertilizers, depends 

 in the majority of cases, on the amount and the particular form of 

 two or three essential articles of plant food, i. e., phosphoric acid, 

 nitrogen and potash, which they contain. To ascertain by this mode 

 of valuation, the approximate market value of a fertilizer, (i. e., the 

 money-worth of its essential fertilizing ingredients,) we multiply the 

 pounds per ton of nitrogen, etc., by the trade value per pound ; the 

 same course is adopted with reference to the various forms of phos- 

 phoric acid, and of potassium oxide. We thus get the values per ton 

 of the several ingredients, and adding them together, we obtain the 

 total valuation per ton in case of cash payment at points of general 

 distribution. 



The market value of low-priced materials used for manurial pur- 

 poses, as salt, wood ashes, various kinds of lime, barnyard manure, 

 factory refuse and waste materials of different description, quite fre- 

 quently does not stand in a close relation to the market value of the 

 amount of essential articles of plant food they contain. Their cost 

 varies in different localities. Local facilities for cheap transporta- 

 tion and more or less advantageous mechanical condition for a speedy 

 action, exert as a rule, a decided influence on their selling price. 



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 different articles of plant-food throughout the soil. 



