EXPERIMENT STATION. 25 



1881. 1882. 1883. 

 ^Cents per pound.^ 



Phosphoric ACID soluble in water, l^ 12| 11 



" " " reverted " and in Peruvian Guano, 9 9 8 



■' " insoluble, in fine bone, lish guano and super- 

 phosphates, - -- 6 G 6 



'• " insoluble, in fine medium bone, 5^ 5i 5i 



'• ■ " " in medium booe, 5 5 5 



'' " " in coarse medium bone, 4^ 4| 4| • 



" " " in coarse bone, bone ash and bone 



black, 4 4 4 



" " insoluble, in fine ground rock phosphate, 3^ 3 2^ 



Potash in high grade sulphate, — — 71 7 7 



" in low grade sulphate and kainit, 5-| 5 4^ 



" in muriate or potassium chloride, — - 4^ 5 4^ 



These ^^ trade-values^^ of the elements of fertilizers are not fixed, 

 l)ut vary witli the state of the mai'ket, and are from time to time 

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

 tion, because the same article sells cheaper at commercial or man- 

 ufacturing centers than in country towns, cheaper 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 ingredients, and 

 adding them together we obtain the total estimated value per ton. 



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

 l3y 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 in the sample, by the per cent, of each 

 grade, taking one one-hundredth of that product, multiplyino- 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 47. 



The 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 \)Y\ce is reason- 

 able. If the selling price is but |2 to 13 per ton more than the 

 ■estimated value, it may still be a fair price ; but if the cost per 

 3 



