FIXATION OF FREE NITROGEN. 



147 





vV?- j. 



*&' 



25 OCT »i»S9 



s\M> v \sH. SAM) \ ASH, GARDEN 



STERILIZED. Ml( TU)K£-SI HI ) I . I ► . soil. 



Pot 1. 



Pot 2. Pot 3. 



Fig. 4— VETCHES. 



Pot 4. 



