VOLATILE ANTISEPTICS AND SOIL ORGANISMS. 149 
life, with perhaps one exception, are totally destroyed. Fred, 
in addition to his study with soils, studied certain types of 
soil organisms in liquid cultures and found that the addi- 
tion of certain strengths of various antiseptics stimulated 
development. This strength varied with different organ- 
isms and the stimulative effect diminished gradually from 
the maximum in both directions. 
EXPERIMENTAL. 
The work outlined in this paper has to do primarily 
with the effect of CSe, toluol, and, to a less extent, chloro- 
form, upon the number of bacteria and the number of 
types of animal life before and after the application, in 
varying quantities, of such substances to soils. 
EFFECT UPON THE NUMBER OF BACTERIA. 
In studying the effect of such chemicals upon the num- 
ber of bacteria in soils, the following methods were em- 
ployed: the sample of soil to be studied was carefully 
freed from worms, etc., and sieved to either remove or 
break up all large particles, then thoroughly mixed. 
Sufficient water was added with that already present to 
bring the content up to one-third or one-half saturation, 
usually one-half. The desired quantity was then weighed 
into a sterile dish, care being taken to prevent contamina- 
tion. The desired quantity of chemical was then added and 
mixed in; the dish was covered with a glass to prevent evapo- 
ration and set aside at room temperature for the desired 
length of time. In some experiments the treated soil was 
removed to sterile bottles, in which case the bottles were 
tightly stoppered with cork or even sealed. No differences 
~ were to be noted following these slightly different methods. 
The per cent of chemical added was in every case based upon 
dry weight of soil—dried at 110° C. for two hours. 
Analyses of all soils were made as follows: the complete 
sample of soil was thoroughly mixed with a sterile spatula 
and several small portions taken from different parts of 
