300 



CHARLES B. LIPMAN 



when the latter are both toxic, as well as when one of them is 

 toxic and the other stimulating. Thus, the undoubted antago- 

 nism shown to obtain between NaCl and Na2S04 gives an un- 

 equivocal reply to the assertion which might be made, on the basis 

 of the other two tables, to the effect that antagonism between the 

 ions only exists when one of them exercises a stimulating effect, 

 which, to a considerable degree, is true of Na2C03 in respect to 

 ammonification. 



ANTAGONISM BETWEEN ANIONS AS AFFECTING NITRIFICATION 



The experiments dealing with this phase of the subject were 

 even more elaborately arranged than the foregoing work in that 

 reciprocal series were run in all cases. In other respects the 

 cultures were prepared like those in the ammonification series 

 except that 1% of dried blood instead of 2% was used. All 

 other explanatory data are given in the following tables. 



Nothing can be more convincing proof of the existence of 

 antagonism between anions than the foregoing figures obtained 

 from the nitrification experiments. Not only does antagonism 

 between the anions prevent injury to the nitrifying flora in the 

 case of salts which are only moderately or slightly toxic, but it 

 does so most markedly in cases in which extremely toxic salts 

 are employed. 



TABLE IVa 



Na2S04 versus NaCI 



