PROFESSOR SCHOENBEIN ON SPONTANEOUS NITRIFICATION. 
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Now, if a nitrate happens to be formed in treating-, for instance, hydrate of lime 
with ozonized atmospheric air, it seems to follow that the nitric acid formed under 
those circumstances, owes, in some way or other, its origin to ozone, pure atmo- 
spheric air being unable to produce a nitrate with the hydrate named. But in what 
manner does ozone contribute to the formation of that acid ? My experiments have 
shown that ozone is a very powerful oxidizing agent, so much so, that even iodine 
and silver are at the common temperature transformed into iodic acid and peroxide 
of silver. If it be a fact that the chemical powers of the oxygen contained in ozone 
are so much exalted as to enable that oxygen to unite with substances so little 
oxidable as iodine and silver are, it would not appear in my eyes very surprising 
if that same oxygen should happen to combine, under certain circumstances, with ni- 
trogen to form what is called nitric acids. 
According to my opinion (see my little work on the Slow and Rapid Combustion 
of Bodies) there does not exist a compound of nitrogen =N0 5 . I consider what 
chemists call the first hydrate of nitric acid as N() 4 +H0 2 , and the normal nitrates 
as N0 4 +R0 2 . Nitrate of lime is therefore to me N0 4 +Ca0 2 . Agreeable to that 
view, I am inclined to account for the nitrification above mentioned in the following 
manner. Ozone transforms first CaO into Ca0 2 , a change which, according to my 
recent experiments, a number of basic oxides undergo within an ozonized atmo- 
sphere. The oxides of manganese, lead, cobalt, nickel, and silver, for instance, are 
readily transformed by ozone into their corresponding peroxides. Whilst peroxide 
of calcium is formed, ozone exerts an oxidizing influence also upon the nitrogen con- 
tained in atmospheric air, and forms N0 4 , which uniting to Ca0 2 , produces what we 
call nitrate of lime. 
The fact, that electrical sparks passing through a moist mixture of oxygen and 
nitrogen generate nitric acid, was first ascertained by Cavendish, 1785 ; in 1840 I 
made the observation that under the same circumstances ozone is produced. Davy 
has found that traces of nitric acid are formed around the positive electrode if a 
current passes through water containing atmospheric air or nitrogen, and I have 
ascertained that under the same circumstances ozone is generated. 
From the facts above stated, it appears that during the slow combustion which 
phosphorus undergoes in moist atmospheric air nitric acid is formed, and we are now 
well aware that ozone makes its appearance at the same time. The invariable con- 
comitance of the two phenomena mentioned, i. e. the contemporary formation of nitric 
acid and ozone which takes place under circumstances apparently so very different 
from each other, gives room to suspect that the production of one of those compounds 
is in some way or other connected with the generation of the other. 
As electrical sparks are able to produce ozone out of moist and otherwise pure 
oxygen, it appears that the formation of that substance is entirely independent of the 
generation of nitric acid, and it becomes highly probable that the ozone produced, 
under electrical influence, out of moist atmospheric air has nothing to do with the 
