THE NITRIFYING PROCESS AND ITS SPECIFIC FERMENT. 
123 
Bottle No. 1 {' 2 nd Gerieration), inoculated on June 28, 1889, was thus examined on 
November 21, 1889, and found to contain :—■ 
Ainruoiiiacal nitrogen = 5'76 parts per 100,000 
Nitrous ,, = 6'43 ,, 
Nitric = 0 ,, 
22 ;id Generation of Direct Series from Garden Soil (see p. 113), inoculated on 
February 2, 1889, was examdned on December 20, 1889, and found to contain :— 
Ammoniacal nitrogen = 0 parts per 100,000 
Nitrous ,, = lOYl ,, 
Nitric ,, = 0 ,, 
23rd Generation of Direct Series from Garden Soil, inoculated on May 20, 1889, 
was examined on November 28, 1889, and found to contain :— 
Ammoniacal nitrogen, not determined 
Nitrous „ = 8'92 parts per 100,000 
Nitric = 0 
The Ammoniacal Solution used in these experiments was found to conttiin on 
November 21, 1889 :— 
Ammoniacal nitrogen = 11T2 parts per 100,000. 
From the above results it appears, therefore, that the pure growth had converted 
more than one-half of the ammoniacal nitrogen into nitrous nitrogen in less than 
live months, whilst no nitric nitrogen had been formed. The impure growths contained 
in the 22nd and 23rd generations had also only given rise to nitrous without any 
nitric nitrogen, even in the course of ten and a half months. In fact, in the case of the 
22nd generation, the whole of the ammonia had been almost quantitatively converted 
into nitrous nitrogen. 
That in the case of “ Bottle No. 1 (2nd generation),” the sum of the ammoniacal 
and nitrous nitrogen is in slight excess of the ammoniacal nitrogen present in the 
original solution employed is probably due to the bottle in which this 2nd generation 
had undergone nitrification having been considerably larger than the others, and 
consequently more concentration by evaporation through the cotton-wool stopper 
must doubtless have taken place. 
In order to put this point to the test, we, later on (February 15, 1890), again took 
a similar large bottle, in fact, a duplicate of No. 1 above, and found 
N as NH.. = 4'53 parts per 100,000 
N ns NjO. = 8-00 
Total N = 12-53 
K 2 
5’ 
