1912.1 



PUBLIC DOCUMENT — No. 'M 



55 



able phosphoric acitl from this source has cost on the average 

 6.11 cents. 



Fifteen samples of acid phos])hate have been examined and 

 all but 2 were found well up to the minimum guarantee. No 

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

 of available phosphoric acid from acid phosphate has cost 5.4-i 

 cents. 



Seven samjiles of basic slag plios})hate have been analyzed and 

 all were found well up to the guarantee. The jtound of avaihible 

 phos})lioric 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 kigJi-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 $18 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 : — 



