1912.1 



PUBLIC DOCUMENT — No. 31. 



55 



able phosphoric acid from this source has cost on the average 

 6.11 cents. 



Fifteen samples of acid phosphate have been examined and 

 all but 2 were found well up to the minimum guarantee. Xo 

 commercial shortage of over 50 cents a ton occurred. The pound 

 of available phosphoric acid from acid phosphate has cost 5.41 

 cents. 



Seven samples of basic slag phosphate have been analyzed and 

 all were found well up to the guarantee. The pound of available 

 phosphoric acid from basic slag, as determined by Wagner's 

 method, has cost on the average 5.12 cents. 



(/) Grades of Fertilizer. 

 The grouping of the complete fertilizers into three different 

 grades furnishes a convenient means of showing the superior ad- 

 vantages to be derived from the purchase of high-grade fertil- 

 izers. In the tables below the high-grade fertilizers are repre- 

 sented by those brands having a commercial value of $24 or over 

 a ton; the medium grade by those which value between $18 and 

 $24 ; and the low grade by those which value $1 8 or less per ton. 

 A table showing average cash price, commercial value, money 

 difference between cash price and valuation, and percentage dif- 

 ference of the three grades of fertilizer follows : — 



