Prof. Clausius on the Nature of Ozone. 49 



must be first freed from such combination before they can be in 

 a state fit for combination with other substances. 



In this respect ozone is comparable with oxygen in the nas- 

 cent state, with the exception that with the latter the electrical 

 condition must be taken into account in addition ; for when 

 oxygen is evolved out of a compound in which it was electro- 

 negative, it will for two reasons easily enter into another com- 

 bination in which it has also to play an electro-negative part : 

 first, because the atoms are still in the sepai-ate state ; secondly, 

 because they already are in the proper electrical condition. 

 Hence oxygen in the nascent state may in many cases surpass 

 ozone in activity. 



The galvanic polarization of a plate of platinum, by immersion 

 in ozonified oxygen, is related to the above action. It is known 

 that the two electrodes, which serve for the galvanic electrolysis 

 of water, become thereby polarized in such a manner as to be 

 capable of giving rise by themselves to a current in the opposite 

 direction. This is explained by supposing the one electrode to 

 be covered by a layer of hydrogen, and the other with a layer of 

 oxygen ; and such explanation accords with the fact that a plate 

 of platinum, when immersed in hydrogen, acquires thereby also 

 a positive polarization. But if a platinum-plate be immersed in 

 common oxygen, the corresponding phsenomenon, which might 

 perhaps be expected, namely the acquirement of negative polarity 

 by the plate, does not occur; and this appears to contradict the 

 above-given explanation. I imagine, however, that this difference 

 may be accounted for as follows : — Inasmuch as a molecule of 

 water consists of two atoms of hydrogen and one atom of oxygen, 

 the atoms of hydrogen, which, like the atoms of oxygen, are also 

 combined two and two to molecules, may enter into combination 

 with oxygen without separating from one another. The atoms 

 of oxygen, on the contrary, as long as they are combined to- 

 gether as molecules, are not in a suitable condition for combina- 

 tion with the hydrogen. Hence oxygen, in its ordinary state, is 

 incapable of causing galvanic polarization, but acquires this 

 power by ozonification. 



Besides an oxidizing action, ozone may exert an opposite or 

 deoxidizing one, as Schcinbein has proved in the case of per- 

 oxide of lead; the ozone itself behig converted thereby into 

 ordinary oxygen. Now, as this transformation of ozone into 

 oxygen occurs also when it is brought into contact with other 

 peroxides, it innncdiately suggests itself that the deoxidatioii of 

 the peroxide is also not confined exclusively to the peroxide of 

 lead. This action may be explained without difficulty. If we 

 imagine an oxide which readily gives up the whole, or a part of 

 its oxygen, in contact with a gas in \^'hich separate oxygen- 

 atoms are moving about, seeking to combine with second atoms, 



Phil. May. S. 4. Vol. 16. No. 104. Mihj 1858. E 



