ANTAGONISM BETWEEN ANIONS 297 



antagonism existed between the anions of those salts and whether 

 it existed for both soil bacteria and for the higher plants. The 

 results of researches which were inaugurated to test these points 

 have been most gratifying and some very striking examples of 

 existing antagonism under the conditions named have been ob- 

 tained in the cases both of the plants and of the bacteria. For the 

 purposes of this paper only the latter phases of the subject can 

 be dealt with. 



ANTAGONISM BETWEEN ANIONS AS AFFECTING AMMONIFICATION 



Ammonification, which is the process by which organic nitro- 

 gen is transformed to the ammonia form, in soils, is carried out 

 by many different species of bacteria working at the same time 

 but not necessarily in the same direction. However, since 

 organic nitrogen must be transformed into nitrates through the 

 agency of the nitrifjdng bacteria it was deemed wise to study the 

 effect of salt antagonisms as between anions first with respect to 

 ammonification and then with respect to nitrification so as to 

 determine how the general process of nitrogen transformation 

 in soils is affected by them. 



The method employed in the ammonification experiments 

 was as follows: To 100 gram portions of a light sandy soil with a 

 good ammonifying and good nitrifying power, placed in tumblers, 

 were added 2 grams of dried blood and the "different salts (as 

 indicated in the tables given below). Enough sterile distilled 

 water was added to make optimum moisture conditions and the 

 mixture stirred with a sterile spatula. The tumbler was covered 

 with a Petri dish cover and allowed to incubate for a week at 

 28° to 30°C. At the end of the incubation period the soil was 

 transferred to copper distilHng flasks, 300 to 400 cc. of distilled 

 water and an excess of magnesia added, and the ammonia was 

 distilled into standard acid, the excess of the latter being titrated 

 against standard ammonia. The salt additions were made on 

 the basis of their toxicities which were determined in investiga- 

 tions described elsewhere.^ All determinations were run in 



* Cent, fiir Bakt., vol. 32, p. 58; vol. 33, p. 305; vol. 35, p. 647, 2*« abt. 



