170 



JAMES M. SHERMAN 



The effect of volatile antiseptics upon the subsequent development 

 of bacteria and protozoa in soil 



It was thought that some hght might be thrown upon the 

 protozoan theory by making bacterial and protozoal counts 

 on soils subsequent to treatment with volatile antiseptics. If 

 this theory is correct we would expect to find the greatest num- 

 ber of bacteria in partially steriUzed soil at a time when the 



TABLE XXX 



Effect of volatile antiseptics upon the bacteria and protozoa in soil 



Fifteen days after treatment 



protozoa are depressed. This, however, does not appear to be 

 the case as is shown by the following experiment. Determina- 

 tions were made of the numbers of bacteria and protozoa in 

 treated and untreated soils at intervals of fifteen days after 

 treatment. The results of this test are given in Table XXX. 



This table shows that the maximum number of bacteria is 

 not found while the protozoa are depressed, but rather that 



