VOLrMETEIC EELATIONS OE OZONE. 
127 
were passed through the gas, the greater part of the contraction was, as in the case of 
oxygen, destroyed. Heat acted in the same direction, but did not restore the gas 
altogether to its original volume. 
On continuing to pass the silent discharge, the gas continued to contract, and the 
deposit to increase on the positive wme. Portions of the same deposit were also scattered 
about the sides of the tube, being probably thrown off from the same wire. The expe- 
riment was in some cases continued till the gas had contracted to about one-third of its 
original volume. To effect this contraction, the machine had to be worked for sixty 
hours. The residual gas consisted of carbonic acid, oxygen, and undecomposed carbonic 
oxide. A similar deposit was obtained when the discharge took place between gold 
instead of platinum wires. This deposit appeared to be soluble in water. Its quantity 
was so small that direct analysis was altogether impossible. Its composition may, how- 
ever, be determined by fixing with precision the ratio of the volumes of the carbonic 
acid and oxygen produced. We have succeeded in devising a method by which this 
analysis may be effected even with less than 0’5 cub. cent, of the mixed gases, but this 
part of the investigation is still unfinished. 
Atmospheric Air is the only gaseous mixture which we have exposed to the action of 
the silent discharge. Like pure oxygen, it undergoes a diminution of volume ; but the 
operation is more quickly terminated and the contraction is less than with that gas 
alone. If, after the passage of the discharge, the vessel be set aside for some hours, the 
contraction will be found to augment ; and if the gaseous mixture be now again exposed 
to the action of the discharge, a further contraction will take place. On the other 
hand, heat destroys a portion only of the contraction at first produced. All these 
facts are easily explained from the simultaneous formation of ozone and one of the 
higher oxides of nitrogen, and the marked influence of the latter, when formed, in 
aiTesting the formation of the former. To the same cause we have succeeded in 
refenlng an apparently anomalous state of oxygen, produced by passing a stream of 
strong electrical sparks, for some minutes, through that gas containing a trace of nitrogen. 
The oxygen becomes by this treatment incapable of contracting or of changing into 
ozone under the action of the silent discharge, and only recovers its usual condition by 
exposure to heat or by standing for some hours. If the nitrogen amounts to not more 
than -g-^oth of the entire volume, this condition cannot be produced more than two or 
three times. At first we supposed it to be a new (passive) state of oxygen, but we have 
now no hesitation in referring it to the presence of a trace of hyponitric acid gas pro- 
duced by the electrical sparks. 
§ 7 . 
It is perhaps premature to attempt a positive explanation of the facts now described 
regarding ozone. The foregoing investigation into its volumetric relations has, for the 
moment, rather increased than diminished the difficulty of determining the true nature 
of that body. To reconcile the experimental results with the view that ozone is oxygen 
