236 ORIGIN OF THE NITRATES. 



each year. The leaves of trees contain about *008 of nitrogen, 

 wheat straw about '003. 



Now, the nitrogen fixed upon the dextrine, in the experiments, 

 at the end of eight months, amounted to about '002 (p. 232), i.e. 

 a nitrogenous substance was formed of a richness almost com- 

 parable to that of herbaceous tissues, produced in vegetation in 

 the same space of time, with the help of the influences exercised 

 by natural electrical tensions, which may be compared to those 

 of the foregoing experiments. 



14. This new cause of the fixing of the atmospheric nitrogen 

 in nature is of the highest importance. It engenders condensed 

 nitrogenous products of the humic order, so widely diffused over 

 the surface of the glode. However limited the effects may be 

 at each moment and at each point of the terrestrial superficies, 

 they may, however, become very considerable, on account of 

 the extent and continuity of a reaction working universally and 

 perpetually. 



