312 AGRICULTURAL EXPERIMENT STATION. [Jan. 



* Not determined. 



Arrangement of the Experiment. 

 Eighteen pots were used in the experiment, fertilized as 

 follows : — 



Pots 1, 4, 7, 10, 13, 16 were infected with a small quan- 

 tity of cultivated soil, in order to note if the infection facili- 

 tated the nitrification of the organic nitrogen in case of our 

 experiments. To each of these pots were also added 10 

 grams of air-slacked lime. 



Filling the Pots. 

 About an inch of ffood clean gravel was first added to the 

 pots, and then five centimeters of the well-mixed soil (three 

 and one-half pounds). The fertilizer (one-half of the nitrate 



