No. 5. DEPARTMENT OF AGRICULTURE. 451 



does not exceed the available nitrogen by an amount equal to most 

 of the 'inactive,' and the selling price, corrected for freight differ- 

 ence, is not considerably less than that asked for fertilizers of like 

 general compo.sition but supplying nitrogen derived from high-grade 

 goods such as bear the index 'a' or even 'b,' there is a reason to believe 

 that the buyer is being subjected to unfair treatment. 



Section 1 of the Fertilizer Law of 1909 requires that the guaranty 

 for a fertilizer shall state 'the percentage such fertilizer contains of 

 nitrogen in an available form.' It is, however, by no means clear 

 that the term 'available,' as used in the law, means precisely the 

 same thing that is meant by that term when used to designate the 

 sum of the water-soluble and active insoluble niti'ogen, as determined 

 by the present method. For some nitrogenous fertilizer ingredients 

 alAvays regarded as of high grade, such as dried blood, meat tankage, 

 and cottonseed meal, contain considerable fractions of inactive insol- 

 uble nitrogen when examined by this method. Until further notice, 

 therefore, the law will not be construed to require that the amount 

 of nitrogen guaranteed shall not exceed that present in a form that 

 will appear as 'available' by the alkaline permanganate method now 

 in use. 



In many of this season's samples, however, the quantity of nitro- 

 gen thus available is found equal to the percentage guaranteed. On 

 the average, the 'available' nitrogen found was 1.49 per cent, the 

 total, 1.81, that guaranteed, 1.69 per cent. 



