RECLAIMING LOST NITROGEN 135 



way to solve this problem has been prepared already. 

 The secret has been discovered. The rules are being 

 practiced by many to-day : they are easily performed : 

 they are very practicable. In short, nitrogen free may 

 be so treated and trained that it readily acquires its useful 

 habits again, so that plants may use it just as they did 

 in other days before freedom was given it. 



Nitrogen fixation in the soil is now a reality, as it has 

 been a reality always. The secret has just been revealed 

 to us: the story has just been told. 



Nitrogen is fixed in the soil. The little microscopic 

 plants within the soil are the agents of nitrogen fixation, 

 not those that once released it, nor those that cause the 

 decay and putrefaction of organic forms that hold it, nor 

 yet even those that change low nitrogen forms into ni- 

 trate salts none of these. Other kinds of bacteria, other 

 tribes, are the agents of fixation. While similar in all 

 habits of life, their work is not destructive. It is con- 

 structive and of another order, entirely, than these hereto- 

 fore mentioned. 



Nitrogen-fixation bacteria call to the air, and. in re- 

 sponse to this call, nitrogen leaves its atmospheric en- 

 vironments, sroes to the bacteria making the call, and does 



o o 



their bidding. 



Our scientific men, to-day, tell us with positiveness that 

 outside of electric discharge at least two ways are open 

 for nitrogen fixation: (i) The acquisition of free nitro- 

 gen, through the agency of bacteria, in the soil ; (2) the 

 acquisition of free nitrogen by bacteria that live on the 

 roots of leguminous plants. 



In reference to the first proposition, it has been proved, 

 abundantly, that atmospheric nitrogen is fixed in the soil 

 in some way ; most probably it is associated with the 

 growth of micro-organisms. This is rather clearly shown 



