10 



on the Florida ground phosphate or the South Carolina floats 

 in converting the insoluble into soluble phosphate. The 

 variation in the results though favoring to some extent the 

 conclusion that there is a slight increase in the available 

 phosphoric acid, may be accounted for on the ground of per- 

 sonal error, or the want of uniformity in the mixing of the 

 materials, since it is difficult, if impossible, to secure perfect 

 uniformity — in a mixturfe of ground phosphate and cotton 

 seed. 



If decomposing organic matter renders insoluble phos- 

 phates available as plant food to any considerable extent, the 

 question of cheap phosphates will be solved and the farmer 

 enabled to purchase fertilizers at a much less cost than at 

 present. That so desirable a result may be reached, is the 

 wish of all who are interested in developing the great agri- 

 cultural industry of our country. The conclusion from these 

 experiments is certainly favorable to the use of floats or 

 finely ground natural phosphates in place of commercial acid 

 phosphates, especially when mixed with cotton seed or cotton 



seed meal. 



STATE LABOEATORY. 



Agricultueal and Mechanical College. 



Auburn, Ala., June 1, 1893. 



Hon. H. D. Lane, 



Commissioner of Agriculture, 



Montgomery, Ala. 



Dear Sir: Enclosed please find tabulated results of 

 Analyses of Commercial Fertilizers, materials used in their 

 manufacture, natural phosphates, etc., made in the State 

 Laboratory from July 1, 1892, the date of my last published 

 report, to June 1, 1893. 



