142 MAINE STATE COLLEGE. 



An Experiment to Test the Relative Ability of Different 



Crops to Obtain Phosphoric Acid From Crude 



Phosphates. 



This experiment was conducted for the Station by H. L. 

 Leland, of East Sangerville, on a slaty gravel soil. Great credit 

 is due him for the care with which the details of the work were 

 carried out. 



A field of three acres, whose dimensions were 20 rods by 24 

 rods, was divided into three parts, each containing just an acre, 

 with dimensions 8 rods by 20 rods. To the first acre there were 

 applied 500 lbs. of dissolved bone black and 100 lbs. of nitrate of 

 soda ; to the second acre there were applied 1000 lbs. of raw 

 South Carolina rock and 100 lbs. of nitrate of soda ; to the third 

 acre, 500 lbs. of a Caribbean Sea guano and 100 lbs. of nitrate 

 of soda were applied. 



Each acre was then divided into twenty plots one rod wide and 

 eight rods long, containing one-twentieth of an acre, and seeded 

 as shown in the opposite diagram : 



