1916] ~ WILLIAMS—NITROGEN FIXATION a17 
noteworthy. It appears that where there is some development 
- of the nitrifying flora in the soil originally the effects of lime are 
decidedly more evident than in those soils apparently devoid of 
nitrifying power. The results of these tests are not to be construed 
as evidence depreciating the effect of lime on-nitrification. They 
are contributory to the fact that the nitrifying flora of a soil cannot 
be developed merely by the use of lime in the absence of other 
factors more fundamental in their influence than is lime itself. 
There was no formation of nitrates whatever under the influ- 
ence of 2 per cent mannite. It not only failed to afford a source of 
energy for the nitrifying ferments, but exerted a depressing effect _ 
on the activities of such as were present. Smaller quantities of 
various sugars (0. 5 per cent) have in some instances exerted a bene- 
ficial effect on nitrification. The quantity used in these tests was 
possibly large enough to have a toxic effect on the soil organisms. 
It seems well established, however, that a satisfactory pabulum for 
nitrifying organisms cannot thus be so readily established. 
VIRGINIA AGRICULTURAL EXPERIMENT STATION 
BLACKSBURG, VA. 
5 CoteMAN, L. C., Untersuchungen iiber nitrifikation. Centralbl. Bakt. 207: 401. 
1g08. 
