wl 
F. H. Storer—Ferment-theory of Nitrification. 447 
during ten days, and the contents of the bottles were then 
tested as before for nitrites and nitrates. But no reaction was 
obtained in either instance, with the exception of No. 12 (cot- 
ton rags, etc.), which gave a faint coloration of a not very sat- 
isfactory character. After the application of the test those of 
the bottles which still contained a sufficiency of liquid were 
re-attached to the aspirator and air was drawn through them 
continually during another week, when the test for nitrites and 
nitrates was again applied. But in no case was there any reac- 
tion, with the exception of bottle No. 8 whose contents gave a 
faint coloration. 
tents of the bottles were then tested for nitrites and nitrates, 
but no reaction was obtained in either case. To make sure 
that the absence of the reaction was not due to any interference 
caused by the presence of the peat or the chemicals, a fresh 
portion of liquid was taken from each of the bottles, enough 
nitrate of potash to amount to 0-001 gram of N,O, was added, 
and the test for nitrites and nitrates was applied in the usual 
way: reactions were now obtained immediately in every 
instance. : : 
In the light of the facts observed by Schldsing, the natural 
inference from the results of these experiments is that the for- 
mation of nitrates or nitrites in bottles Nos. 7 to 10 of the first 
series of experiments was due to the presence of living organ- 
isms which the peat had harbored, and that the absence of 
nitrification in the other series of experiments is to be attrib- 
uted to the destruction of the ferment-germs by the hot acid 
with which the peat employed in these gh one had been 
treated. It is to be observed, moreover, that the formation of 
nitrogen oxides in the bottles Nos. 7 to 10 is in nowise out 0 
