19 



The valuations as published in our tables mean the 



Commercial comparative cash cost of an amount of nitrogen, phos- 



Valuation of phoric acid, and potash in unmixed staiidard chemicals 



Fertilizers, and raiv mateiiais of good quality, corresponding with 

 the same amount found in a ton of the fertilizer in 

 question. The water soluble nitrogen has been valued at i8j^ 

 cents per pound ; the organic nitrogen, assumed in all cases as com- 

 ing from the highest grade of raw materials, has been valued at 

 20^-j cents per pound — this is manifestly unfair in instances where 

 low grade sources of organic nitrogen are used, and gives such 

 fertilizers too high a value. It certainl)* creates an unfair competi- 

 tion between the manufacturer who used only high grade materials 

 and the one who used the cheaper or low grade substances in his 

 mixed product. There is great need of some recognized official 

 method of determining the availability of the organic nitrogen in 

 mixed commercial fertilizers. Much good work has been accom- 

 plished along this line by Jenkins' and also by Jones', although the 

 methods as outlined have not yet been adopted as official by the 

 Association of Official Agricultural Chemists. It is the intention of 

 this station to give this matter further consideration. 



Soluble phosphoric acid has been valued at 5 cents, reverted at 

 4^2 cents and insoluble at 2 cents per pound. Phosphoric acid in 

 fine bone and tankage has been valued at 4 cents, and in coarse 

 bone and tankage at 3 cents per pound. The phosphoric acid in 

 basic slag has been valued according to its content of available phos- 

 phoric acid as shown by Wagner's method, the available phosphoric 

 acid being valued at 4 cents and the insoluble at 2 cents per pound. 



In the table of analyses, whenever the potash is reported without 

 foot-note or comment, it may be understood that sufficient chlorine 

 was found present to unite with all of the potash. In cases where 

 part of the potash is found present as sulphate or carbonate, and the 

 analysis indicates the presence of chlorine, the potash equivalent of 

 the chlorine is first calculated and the remainder is counted as 

 sulphate or carbonate as the case may be. 



The presence of chlorine or sulphates in a fertilizer advertised to 

 contain its potash in form of carbonate is manifestly just as objection- 

 able as though they were in actual combination with the potash. 

 Total potash has been reported in form of a foot-note in instances 

 where it is evident that organic vegetable substances have been 

 used in the fertilizer. No attempt has been made to value that part 

 of the potash which is insoluble in water. 



' Connecticut State Exp. Sta. Repts. 1893, 1S94-1S96. 

 2 Vermont Exp. Sta. Repts. iSqS, 1S99, 1901. 



