134 



HATCH EXPERIMENT STATION. 



[Jan. 



dryness, char, and abstract with dilute nitric acid. Filter 

 and wash thoroughly with water. Burn the residue to a 

 white ash, add it to the solution and bring to complete 

 dryness on sand bath. Take up with hot water and a few 

 cubic centimeters of nitric acid. Digest for one-half hour. 

 Filter and wash thoroughly, and determine phosphoric acid 

 in the solution in the usual way. 



Results of Analyses of Soils for Available Phosphoric Acid, by 

 Methods previously described (Soil from Fields of Massachusetts 

 Agricultural College Farm). 



Analysts: Henri D. Haskins. 



Charles I. Goessmann. 



Conclusion. 

 The several modes used by us in determining the amount 

 of available phosphoric acid contained in the soil under ex- 

 amination have given different results. The difference in 

 the amount of available phosphoric acid found by any of the 

 modes of analysis employed does not correspond with the 

 actual yield of the several plats in the field. The results 

 of our investigation are more of a suggestive than decisive 

 character. The work will be continued as far as resources 

 on hand will permit. 



6. Analysis of Drainage Waters obtained from 



Field A of the Hatch Experiment Station. 



The field under discussion has been from 1883 to date 



treated in a systematic way with commercial fertilizers, in 



the manner briefly described in the following pages. The 



