262 ANNUAL EEPOKT SMITHSONIAN INSTITUTION, 1908. 



the combustion of nitrogen to its oxides and the transformation of it 

 into cyanogen or ammoniacal compounds have been used. All these 

 methods are practicable and will all probably be productive of 

 results. Which of these results will be the most important it is for 

 the future to decide. In all of them, however, is this characteristic 

 feature — they do not rob Nature of its amassed treasures, nor do they 

 wish to imitate her creations ; they aim merely to assist her in one of 

 her greatest processes, the circulation of nitrogen. If we succeed in 

 influencing this phenomenon, we will also in a measure control that 

 other which is so intimately bound up with our fortune or misfor- 

 tune, the course of life. We will force the earth to greater fertility, 

 to an increasing habitability. 



In such a task Nature herself should be our ally. The savage force 

 of the water which falls from above carries out the chemical work 

 which we call upon it to perform, and a day is beginning to dawn 

 when it will be not only a pretty metaphor, but one of peculiar force 

 and meaning, to speak of the fertile influence of the brooks which 

 ripple down from the mountains into the valle^^s where stand the 

 habitations of men. 



