AGEICULTURAL EXPERIMENT STATION. 5 



leather has been used. Organic nitrogen in mixed goods is there- 

 fore vakied at sixteen cents per pound. As nitrogen in nitrates 

 is rated for 1892 at only a cent less per pound than organic 

 nitrogen, and as with but few exceptions the nitrates are present 

 in very small quantities, no difference has been made in 

 computing the "estimated value" between organic and nitric 

 nitrogen, but both have been valued at sixteen cents. The small 

 increase in the "estimated value" thus caused, while slightly 

 favorable to certain manufacturers, can certainly do the con- 

 sumer no serious harm. The nitrogen present in ammonia salts is 

 reckoned at seventeen and one-half cents. 



The insoluble phosphoric acid of mixed fertilizers is reckoned 

 at two cents per pound, coming as it does largely from mineral 

 phosphates, and in any case being much the least valuable por- 

 tion of the original material. 



The potash is valued at the price of that ingredient in the 

 muriate, unless the chlorine present in the fertilizer is not suf- 

 ficient to combine with it, in which case the excess of potash is 

 reckoned at the price of the sulphate. 



The valuation of a fertilizer is obtained by multiplying the per- 

 centages of the several ingredients by twenty (which gives the 

 pounds per ton), and these products by the prices per pound, and 

 the sum of the several final products is the market value of the 

 fertilizing ingredients in one ton. For instance the "station 

 valuation" of fertilizer No. 855 was obtained as follows : 



2.65% Nitrogen, 53. lbs. per ton @ 16 cts.— $8.48. 



6.26% Soluble Phos. Acid, 125.2 •' '' " @ 7^ " —9.39. 



3.80% Rev. '• '' 76. '^ " " @7 " —5.32. 



1.22%rnsol. " " 24.4'- '' " @2 '• — .49. 



1.77% Potash, 35.4" '^ " @ 4^ ^' —1.59. 



Valuation, $25.27 



Change in Method. 

 In past years separate analyses have been made of the sample^ 

 representing the same fertilizer. At present equal quantities of 

 all the samples are mixed, and an analysis of this mixture is 

 assumed to give the same result as would be reached by averaging 

 the analyses of the several samples, a method which is undoubtedly 

 correct. 



