VOLATILE ANTISEPTICS AND SOIL ORGANISMS. 165 
observed, while the increase in yield was as great as 80%. 
On the same soil, destruction of protozoa by heat followed 
by an enormous increase in bacterial content was not, in 
the case of buckwheat, followed by an increased yield. This 
may be attributed to the production of toxic substances, 
but, with oats, the toxic effect was even more marked at the 
beginning than with buckwheat, and still the increase in 
yield in one instance amounted to 159% on heated soil. 
The writer’s results show, as pointed out by Russell and 
Hutchinson, and Goodsey (36), that numerous types of 
protozoa are to be found in all soils examined. They do not 
show, though, that treating such soils with CS and toluol, 
as has been done in experimental work or with the quan- 
tities used by the above mentioned writers (.2%), render 
such soils free from protozoa. To the contrary, they show 
no appreciable diminution in number of types present. 
This is true of laboratory, greenhouse, and field experi- 
ments. There is no doubt that sufficiently large quan- 
tities will destroy the protozoa, but such quantities are far 
beyond those of experimental practice. No explanation of 
why Russell and Hutchinson failed to observe protozoa fol- 
lowing treatment can be offered, unless it be that their 
methods of examination were at fault. 
The writer’s results thus far regarding the effect of such 
treatment upon bacterial phenomena other than total num- 
ber have been too meagre to report. However, the evidence 
of other writers seems to leave no doubt but that those 
activities which are of practical moment, namely: ammoni- 
fication, nitrification, nitrogen fixation, and denitrification, 
are beneficially effected. (See Lipman, Russell and Hutch- 
inson, and Fred.) 
While protozoa have been shown to be universally present 
in soils, universally beneficial results do not follow the 
application of such chemicals. In the large series of plats 
(140), mentioned earlier in this paper, treated with amounts 
of CSe and toluol varying from 1 to 30 ce. per square foot, 
no beneficial results were observed with any test crops. 
