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 payments 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 diffei'ent localiiies. Local facilities for cheap transportation 

 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 tho 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. 



The state of moisture exerts a uo less important influence on the 

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

 samples of fish fertilizers, although equally pure, may differ from 50 

 to 100 per cent, in commercial value, on account of mere difference 

 in moisture. 



Crude stock for the manufacture of fertilizers, and refuse materials 

 of various descriptions, have to be valued with reference to the 

 market price of their principal constituents, taking into consideration 

 at the same time their general fitness for speedy action. 



