22 THE CONNECTICUT AGEICULTURAL 



These '^trade-values''' of the elements of fertilizers are iiot fixed, 

 but vary with the state of the market, and are from time to time 

 subject to revision. They are not exact to the cent or its frac- 

 tion, because tlie same article sells cheaper at commercial or manu- 

 facturing centers than in country towns, cheajDcr in large lots 

 than in small, cheaper for cash than on time. These values are 

 high enough to do no injustice to the dealer, and properly inter- 

 preted, are accurate enough to serve the object of the consumer. 



To Estimate the Value 'Of a fertilizer we multiply the per 

 cent, of nitrogen, etc., by the trade-value per pound, and that 

 product by 20; we thus get the values per ton of the several in- 

 gredients, and adding them together we obtain the total esti- 

 mated value per ton. 



In case of Ground hone, the fineness of the sample is graded 

 by sifting, and we separately compute the nitrogen value -of each 

 grade of bone which the sample contains, by multiplying the 

 pounds of nitrogen per ton iu the sample, by the per cent, of each 

 grade, taking one one-hundredth of that product, multiplyi»g it 

 by the estimated value per pound of nitrogen in that grade, and 

 taking this final product as the result in cents. Summing up the 

 separate values of each grade, thus obtained, together with the 

 values of each grade for phosphoric acid, similarly computed, the 

 total is the estimated value of the sample of bone. For further 

 particulars, see page 38. 



l^ie uses of the " Valuation'''' are, 1st, to show whether a given 

 lot or brand of fertilizer is worth as a commodity of trade what it 

 costs. If the selling price is no higher than the estimated value, 

 the purchaser may be quite sure that the price is reasonable. If 

 the selling price is but $2 to |3 per ton more than the estimated 

 value, it may still be a fair price ; but if the cost per ton is $5 or 

 more over the estimated value, it would be well to look further. 

 2<1, Comparisons of the estimated values and selling prices of a 

 number of fertilizers will generally indicate fairly which is the 

 best for the money. But the " estimated value" is not to be too 

 literally construed, for analysis cannot always decide accurately 

 wdiat is the form of nitrogen, etc., while the mechanical condition 

 of a fertilizer is an item whose influence cannot always be rightly 

 expressed or appreciated. 



The Agricultural value of a fertilizer is measured by the bene- 

 fit received from its use, and depends upon its fertilizing eifect, or 

 <3rop-producing power. As a broad, general rule, it is true that 



