STIMULATING ACTION 



147 



Stimulating Action. Only six of the twenty-four compounds 

 tested failed to stimulate the ammonifying organisms at some con- 

 centration. Those which did not stimulate were calcium chlorid, 



*T H- M [O CO CO * 



^> w t> ui O m O 



X * * 1 * * *'- 



o S, S, B, , . , . - 



FIG. 20, Graphs showing molecular concentrations at which the various salts exert 

 greatest stimulation on bacteria in soil. 



