mixing presented any advantages over the usual method of ^^°^ ^^^ 

 buying manufactured fertiHzers. ^°^^ 



"In the .following table the actual composition of the J73 

 different mixtures is compared with the calculated composi- 

 tion of a perfect mixture in each case, the analyses of the raw 

 materials and the weights used in the formulas serving as a 

 basis for the calculation. The estimated commercial value 

 of the mixture is also compared with the estimated value 

 of an even mixture of the materials used. 



Table of Analyses and Guarantees. 



"The plus, -j-, and minus, — , signs in the difference 

 column, indicate the percentage more or less found by 

 analyses than was guaranteed. 



"There is a very close agreement between the calculated 

 and actual composition of these mixtures; the widest varia- 

 tion is 0.32 per cent, for Nitrogen, 0.76 per cent, for phosphoric 

 acid, and 0.69 per cent, for potash. In home-made mixtures 

 the value of exactness in composition depends very largely 

 upon the value of the relative proportions of the plant food 

 applied to the soil for the different crops. A pound per 

 acre, more or less, of either Nitrogen, phosphoric acid, or 

 potash would probably not be observed in the results secured 

 from their use. Taking the widest variation in the above 

 mixture it would require 313 pounds to make a difference 

 of one pound in the Nitrogen, 133 pounds in the phosphoric 

 acid, and 145 pounds in the potash. The mixtures do con- 

 tain practically the amount and proportion of plant food that 

 they were intended to furnish, and, therefore, show that 

 farmers are able to make even mixtures of such raiu tnaterials 

 as the market affords. 



