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PROFESSOR P. P. FRANKLAND ARD AIRS. G. C. FRANKLARD OR 
thus clearly showing that the excess of total nitrogen in these large bottles was due 
to the greater amount of concentration by evaporation through the cotton-wool 
stoppers. 
The exclusive production of nitrous nitrogen in these experiments is of special 
interest, as it raises the possibility of there being distinct organisms concerned in the 
formation of nitrites and nitrates respectively ; whilst, on tlie other hand, it is by no 
means impossible that the formation of nitrate may yet take place in these solutions, 
or that the same organism may produce nitrates under other conditions. These are 
points which will require considerably more time to determine.* 
The principal results of our investigation may be summarised as follows ;— 
1. Tlie isolation, by the method of fractional dilution, of a micro-organism present 
in ammoniacal solutions undergoing nitrification originally induced by a minute 
quantity of garden soil. 
2. Idle organism in question is possessed of a characteristic form, being a very short 
bacillus, about 'S/r long, hardly longer than broad, and exhibiting only vibratory motion. 
3. The organism can be cultivated in suitable ammoniacal solutions to which no 
organic matter whatsoever has been added. In such solutions we have cultivated it 
for nearly three years. 
4. In these solutions the growth of the micro-organism is accompanied by the 
gradual transformation of the ammoniacal into nitrous nitrogen, whilst liitherto we 
have not observed the formation of any nitric nitrogen in solutions inoculated with the 
pure growth. 
5. The solutions thus nitrified remain perfectly transparent and pellucid. 
6. The solutions nitrified by inoculating the organism in question, after its purifica¬ 
tion b}^ the process of fractional dilution, have in every case yielded absolutely negative 
results when introduced into gelatine-peptone, the organism, as taken from such 
nitrifying solutions being apparently incapable of growth in this solid medium. 
On the other hand, in the process of purihcation by dilution referred to above, the 
less diluted, and, therefore, presumably less pure portions, invariably yielded growths 
on being introduced into gelatine-peptone. The refusal to grow in gelatine thus serves 
as an invalualde guide in ascertaining the purity of the organism. 
We are at present engaged in the further investigation of this interesting oiganism, 
but in consequence of the large amount of time whi(;h these observations involve, owing 
to the slowness of the process of nitrification, we have deeuied it advisable no longer 
to delay the publication of this first part of our enquiry. 
* In his study of the phenomena of nitrification, Warington (‘ Chemical News,’ vol. 44, p. 217) found 
that ammoniacal solutions seeded from old uitritied solutions generally only yielded nitrites and no 
nitmtes. 
