ATMOSPHERIC AIR AS THE FOOD OF PLANTS. 81 
his experiments nitrogen and water combine to form ni- 
trite of ammonia. 
2N + 2H,O = NH, NOH 
This theory, supported by the authority of so distin- 
guished a philosopher, has been almost universally credit- 
ed.* It has, however, little to warrant it, even in the way 
of probability. If traces of nitrite of ammonia can be 
produced by the immediate combination of these excep- 
tionally abundant and universally diffused bodies at com- 
mon temperatures, or at the boiling point of water, or 
lastly in close proximity to the ames of burning gases, 
then it is simply inconceivable that a good share of the 
atmosphere should not speedily dissolve in the ocean, for 
the conditions of Schénbein’s experiments prevail at all 
times and at all places, so far as these substances are con- 
cerned. 
The discovery of Zabelin that ammonia and nitrous acid 
do not always appear in equivalent quantities or even 
simultaneously, while difficult to reconcile with Schon- 
bein’s theory, in no wise conflicts with any of his facts. 
A quantity of free nitrous acid that admits of recognition 
by help of Price’s test would not necessarily have any 
effect on litmus or other test for free acids. There re- 
mains, then, no necessity of assuming the generation of ni- 
trite of ammonia, and the fact of the separate appearance 
of the elements of this salt demands another explanation. 
The Author’s Opinion.—The writer is not able, perhaps, 
to offer a fully satisfactory explanation of the facts above 
adduced. He submits, however, some speculations which 
appear to him entirely warranted by the present aspects 
of the case, in the hope that some one with the time at 
* Zabelin was inclined to believe that his failure to detect nitrous acid in some 
of his experiments where organic matters intervened, was due to a power pos- 
sessed by these organic matters to mask or impair the delicacy of Price’s test, 
as first noticed by Pettenkofer and since demonstrated by Schénbein in case of 
urine. 
4* 
