NITROGEN, NITRIFICATION, NITROGENOUS MANURES IIQ 



127. Boussingault's Experiments. Boussingault was 

 the first to make a careful study of the subject. In a 

 prepared soil, free from nitrogen, and containing all of 

 the other elements necessary for plant growth, he grew 

 clover, wheat, and peas, carefully determining the 

 nitrogen in the seed. The plants were allowed free 

 access to the air, being simply protected from dust, and 

 were watered with distilled water. But little growth 

 was made. At the end of two months the plants were 

 submitted to chemical analysis, and the amount of ni- 

 trogen present was determined. 



The results are given in the following table :* 



NITROGEN 



Boussingault concluded that when plants growing in 

 a sterile soil were exposed to the air, there was with 

 some a slight gain of nitrogen, but that the amount 

 gained from atmospheric sources was not sufficient to 

 feed the plant and allow it to reach full maturity. By 

 many these results were not accepted as conclusive. 



Fifteen years later (1853) Boussingault repeated his 



