YOLIJIMETEIC EELATIONS OF OZONE. 
129 
which occurs when the electrical discharge is passed through oxygen, is at first sight 
indeed faToiu'able to such a supposition, inasmuch as the combination of gases is usually 
accompanied either by a diminution, or no change of volume. But we have not been 
able to discover, in its other reactions, any facts which countenance this otherwise 
improbable \iew of the constitution of oxygen gas. 
Finally, it remains to be considered, whether in the formation of ozone, oxygen does 
not undergo a more profound molecular change than is involved in an allotropic modifi* 
cation, whether, in short, this supposed element may not be actually decomposed. If, 
for the moment, we confine our attention to the phenomena which present themselves 
when the electrical discharge is passed through oxygen, this attractive hypothesis will 
be found to furnish a simple and plausible explanation of them all. It will be observed, 
at once, that the conditions under which ozone is formed from oxygen by the electrical 
discharge, are precisely those under which other gases, known to be compound, are 
decomposed. The electrical cui’rent is one of very high intensity, and therefore very 
favourable to decomposition : when passed in the form of the silent discharge, a large 
contraction takes place in the volume of the gas, which is partially destroyed by a feAV 
electrical sparks, and wholly by heat. With nitrogen and hych’ogen no similar effects 
are observed, the volume of these gases being quite unaffected by either form of 
discharge. 
The beha'vioiu’ of carbonic oxide, when exposed to the action of the silent and spark 
discharge, corresponds remarkably to that of oxygen ; the latter form of discharge, while 
producing itself only a limited contraction in carbonic oxide, destroying a part of the 
contraction produced by the former. Again, when deutoxide of nitrogen is exposed to 
the action of the same agents, an immediate contraction takes place without any solid 
or liquid product being formed, shorving that in certain cases of gaseous decompositions, 
the resulting gases occupy a smaller volume than the original compound. 
If Ave assume that oxygen is resoh'ed by the electrical discharge into a neAv compound 
(ozone), containing the same constituents as the oxygen itself, but in a different propor- 
tion, and into one of the constituents themselves, in the same manner as carbonic acid 
is resolved into carbonic oxide and oxygen, or nitric oxide into hyponitric acid and 
nitrogen, the results of our experiments will admit of an easy explanation. One of the 
simplest suppositions Ave can make for this purpose is, that tAvo volumes of oxygen con- 
sist of one volume of U and one volume of V, united Avithout condensation (U and V 
being the supposed constituents of oxygen), and that one volume of ozone consists of tAVo 
volumes of U and one volume of V; and further, that by the action of heat, iodine, &c., 
ozone is resolved into U and oxygen. 
The appearance of ozone at the positive pole in the electrolysis of water, and its 
fonnation by the agency of so active a body as ordinary phosphorus, do not seem 
unfavourable to its being the result of decomposition. But the same observation Avill 
not apply to its production by the action of acids on such bodies as the peroxide of 
barium. AVe certainly should not haA’e expected to see a body derived from the decom- 
