tees ee. ee ene Rs ee ee ee f° wi ane —— < == rt * a es le. on BG 
. 
VOLATILE ANTISEPTICS AND SOIL ORGANISMS. 167 
“So richtig auch Halli Thoris in vielen Fallen sein wird, 
so diirfte es doch nicht anginglich sein, dieselbe zu verall- 
gemeinern.” 
GENERAL CONCLUSIONS. 
From the evidence given above, the following conclusions 
appear justifiable :— 
1. That small quantities of CSe, toluol, and chloroform, 
such as have been used practically and experimentally, 
when applied to the soils studied, exert a stimulative rather 
than a diminishing effect upon the total number of bacteria 
present. 
2. That an application of such quantities of CS2 and 
toluol does not have an appreciable effect upon the num- 
ber of types of protozoa present in such soils as have been 
studied. 
3. That a very marked increase in yield may be noted 
following such an application when no evident change 
occurs in total number of bacteria present. 
4. That, in the light of the recent work of Koch, Egoroo, 
Goodsey, Fred, and others, with results presented in this 
paper, the theory advanced by Russell and Hutchinson to 
account for the increased yield following the application of 
such chemicals, appears not tenable for general application. 
The writer wishes to express his appreciation to Dr. Wil- 
liam Trelease, Director of the Missouri Botanical Garden, 
who placed unlimited means at his disposal for carrying 
on this piece of work: to Dr. George T. Moore, at whose 
suggestion the work was undertaken and whose untiring 
directions have rendered the results obtained possible: and 
to Dr. W. C. Curtis, who placed, without reserve, his labora- 
tory and equipment at the writer’s disposal for carrying 
on the protozoalogical end of the work. 
i 
