1910.] PUBLIC DOCUMENT — No. 31. 59 



the availiiltlc j)bos])horie acid guarantee was maintained in all 

 but 1 instance. The pound of available phosphoric acid from 

 this source has cost, on the average, r>,(»9 cents. 



Basic Slag Phosjjhalc. — Six samples have been examined 

 and the available phosphoric acid in all but 1 sample has run 

 somewhat under the amount guaranteed. There has been a 

 connuercial shortage in only one instance, however, as the de- 

 iiciencj was made up bv an excess of insoluble phosphoric acid. 

 The pound of available phosphoric acid (by Wagner's method) 

 from slag has cost, on the average, 5.79 cents. 



(i) Afiscrlhuif'ous Fertilizers, Soils and By-producfs for Free 



Analijsis. 



As in the past, free analyses have been made for farmers and 

 others interested in agriculture so far as our time and facili- 

 ties would warrant. Work of this nature, however, has been 

 done when it would not contiict with the official inspection of 

 commercial fertilizers. Including the materials which have been 

 tested for the various departments of the experiment station, 

 385 analyses have been made. They may be grouped as fol- 

 lows: 292 fertilizers and by-])roducts nsed as fertilizers, G8 

 soils and 25 samples of miscellaneous materials. Information 

 has been furnished each applicant at the time the results of 

 analyses were reported as to the best method of using ferti- 

 lizer materials, also as to their average commercial value. In- 

 formation has also been furnished with soil analyses as to the 

 best method of treating the soil, also as regards the fertiliza- 

 tion of the same. Both the fertilizer materials and soil samples 

 have been taken according to instructions furnished from this 

 office, and are therefore in all cases representative samples. 

 These analyses do not appear in our fertilizer bulletin. 



The fertilizer section has, as in past years, been active in co- 

 operative work with the Association of Official Agricultural 

 Chemists, and also with the fertilizer branch of the American 

 Chemical Society. 



