AGRICULTURAL EXPERIMENT STATION. 6 



The Valuation of Superphosphates and Mixed Goods. 



These trade values are applied to the valuation of Superphos- 

 phates and all mixed goods, as follows : 



It is assumed that the organic nitrogen of these goods has for 

 its source such materials as dried blood, ground fish, or nitroge- 

 nous substances of equally good quality, unless a special examina- 

 tion of some particular brand shows that inferior material like 

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

 fore valued at fifteen and one-half cents per pound. As nitrogen 

 in nitrates is rated for 1891 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 ni- 

 trogen, but both have valued at fifteen and one-half cents. The 

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

 favorable to certain manufacturers, can certainly do the consumer 

 no serious harm. The nitrogen present in ammonia salts is 

 reckoned at eighteen 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 suffi- 

 cient 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 a certain fertilizer was obtained as follows : 



2.34 per cent. Nitrogen equal 46.8 lbs. per ton @ I'-icts $7.25 



5.05 " Sol. phos. acid " 101.0 lbs. " '• (ti 8 cts 8.1 - 



1.48 " Rev. " " " 29.6 '• " " @ 74cts 2.22 



1.96 " Insol. '• " " 39.2 " " " @ 3 cts 1.18 



5.12 " Potash " 102.4 " " " & -Jkts 4.61 



Valuation 623.34 



Change in Method. 

 In past years separate analyses have been made of the three 

 samples representing the same fertilizer. This year and last, 

 equal quantities of the three samples have been mixed, and an 

 analysis of this mixture has been assumed to give the same result 

 as would be reached by averaging the analyses of the three sam- 

 ples, a method which is undoubtedly correct. 



