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, 



Si-" i h3 ro co w 

 g L.T & en o m 



;>, O, 0,0, 



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

 greatest stimulation on bacteria in soil. 



