EXPERIMENT STATION BULLETINS. 347 



position can be compared at a glance with the composition claimed for it 

 by manufacturer. In this way the buyer can see at once by this bulletin 

 whether the fertilizer is as good as the claims made for it. 



WHAT TO LEARN FROM THE ANALYSIS. 



The thr-ee most valuable materials in commercial manures are potash, 

 phosphoric acid, and available nitrogen. Each of these has a commercial 

 value, and the worth of any given quantity in the market may be stated 

 in dollars and cents. Only these three substances are considered in the 

 inspection of commercial fertilizers, because the other materials are of too 

 little value to be purchased at high prices. The essential value of these 

 fertilizers lies in, the potash, phosphoric acid, and available nitrogen they 

 contain. The law does not prescribe the amount of these substances in 

 any fertilizer, but requires the manufacturer or dealer to certify the com- 

 position of the fertilizer, and to deposit a sample of the fertilizer with the 

 secretary of the State Board of Agriculture. In this way the composi- 

 tion of the fertilizer as claimed by the manufacturer is offered to the public. 

 Samples of the fertilizer are gathered in the open market, and analyzed, 

 and the results directly compared with the claims of the manufacturer in 

 the bulletin. The farmer can thus find in the bulletin, on lines opposite 

 each fertilizer, the amount of nitrogen, phosphoric acid, and potash as 

 claimed by the manufacturer, and as actually found by analysis at this 

 laboratory. If the analysis shows more of any given substance than is 

 claimed, the goods are better than claimed; but if much less is found on 

 analysis than is claimed, then the goods are proportionately of less value 

 to the farmer. For example, an Ohio potato fertilizer was sold in the 

 state last year that fell short of the claimed amount of available nitrogen 

 by more than two per cent, and of potash by more than three per cent., 

 and the fertilizer was not worth so much as claimed by $11 per ton. By 

 consulting the tables in the bulletin, the market value of these commercial 

 fertilizers can be estimated on the basis that available phosphoric acid is 

 worth eight cents per pound, insoluble phosphoric acid three cents, potash 

 six cents, and ammonia eighteen cents. As there are 20 times 100 pounds 

 in a ton, if we multiply the value of a pound by 20, we get the value of 

 one per cent, of each substance, and thus obtain a factor for obtaining the 

 value of the material in a ton from the percentage given in the tables of 

 the bulletin. One per cent, means 20 pounds in a ton, and if the material 

 is worth eight cents per pound then each per cent, equals $1.60 per ton. 



Multiply $1.60 by the per cent, of available phosphoric acid. 

 .60 " " insoluble 



" 3,60 " " ammonia. 



1.20 " '= potash. 



The sum will give the market value of a ton of such fertilizer. Take 

 for example Vegetable Bone fertilizer as found last year: 



Ammonia 5.76 % X $3.60= $20.74 



Available phosphoric acid 5.40 % X 1.60= 8.64 



Insoluble " " 1.48 % X .60= .89 



Potash 7.80 % X 1.20= 9.36 







Market value per ton . $39.62 



