74 



as in the notliing-limc series, showing that lime failed 

 to completely overcome the bad effect of the vanillin. 



Table IV. — The Effect of Non-Nitrogenous Substances 



on the Nitrification of Dried Blood, Pyridine, Etc., 



in Norfolk Sandy Loam Soil. Nitrates Expressed 



as p. p. m. of Dry Soil. 



Nitrification of dried blood and piperidine was but 

 slightly reduced by cumarin alone. However, this 

 compound materiall}^ reduced nitrification of pyridine, 

 and inhibited the process with quiiioline. Lime in- 

 creased the toxicity of cumarin to nitrification of pyri- 

 dine, but greatly reduced it to the decomposition of 

 dried blood and piperidine. No nitrates w^ere formed 

 from quinoline with or without lime. In those -in- 

 stances where lime reduced toxicity of cumarin, com- 

 parison with the nothing-lime series shows that the 

 toxicity was not entirely overcome. " 



Salicylic aldehyde completely inhibited nitrification 

 in all cases. 



In all cases, in the very acid soil, the data for which 

 are given in table V. the various nitrogenous com- 

 pounds gave rise to more nitrates than were obtained 

 from the distilled water check. Attention is called to 

 the fact that in this very acid soil, quinoline is nitrified, 

 while in the slightly acid Norfolk sandy loam, it is not 

 nitrified. Lime increased nitrification in each case 

 except in the quinoline and quanidine carbonate 

 treated soil, in which instances lime markedly reduced 

 nitrification. From the data given, it is evident that 

 lime reduces or completely inhibits nitrification of 

 quinoline. On the other hand, this basic compound is 

 apparently most readily nitrified in the soil having 

 the highest acidity. 



