I 



ATMOSPIIEUIC Allt AS THE FOOD OF PLANTS. 81 



his experiments nitrogen and water combine to form ni- 

 trite of ammonia. 



2 N + 2 H,0 - Nil,, NO^H 



This theory, supported by the authority of so distin- 

 guished a philosopher, has been ahnost 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 Avater, or 

 lastly in close proximity to the flames 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 Schonbein's experiments preyail at all 

 times and at all places, so far as these sul)stances are con- 

 cerned. 



The discovery of Zabeliu that ammonia and nitrous acid 

 do not always appear in equivalent quantities or even 

 simultaneously, while difiicult 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 Sch<>nbeiu in case of 

 urine. 



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