2 
DR. ANDRE\yS ON THE CONSTITUTION AND PROPERTIES OF OZONE. 
properties ? And next, what is the composition of ozone, or, if there be more ozones 
than one, how are they respectively constituted ? 
The experiments of Williamson * indicated the production of water, when ozone 
obtained by electrolysis was decomposed by being passed over heated copper, and 
Baumert'I' obtained similar results when he passed a stream of electrolytic oxygen 
through a tube containing anhydrous phosphoric acid, which was heated at one point 
to redness. These experiments were not, however, adapted to yield quantitative 
results, but they led to the general conclusion that this variety of ozone is an oxide 
of hydrogen containing more oxygen than water. But from another and very im- 
portant experiment, to which I shall have occasion hereafter very fully to refer, 
Baumert has concluded that it is a teroxide of hydrogen, HO3. 
On the other hand, the experiments of De la Rive and of Fremy and Becquerel:}: 
have shown, that pure and dry oxygen gas may be converted by the electrical spark 
into ozone. 
I am not aware of any experiments on ozone obtained by the action of phosphorus 
on atmospheric air, which throw any distinct light on its constitution. Marignac 
passed a stream of this ozonized air through a solution of iodide of potassium, till 
the whole of the iodide was converted into iodate of potassa, and concluded that 
ozone produced in this way must be either oxygen in a peculiar state, or a peroxide 
of hydrogen. 
According to the results, therefore, of the most recent investigations, it would 
appear, — 
That the substances comprehended under the name of ozone are not identical ; 
That the ozone obtained by the action of the electrical spark on oxygen gas is 
oxygen itself in an altered or allotropic state ; 
That the ozone obtained by the electrolytic decomposition of water is an oxide of 
hydrogen, having the formula HO3 ; and 
That the ozone obtained by the action of phosphorus on oxygen is either oxygen 
itself, or a compound of oxygen and hydrogen §. 
The subject of ozone has at intervals engaged my attention during the last four or 
five years, and I w'as actually occupied with a series of experiments on the production 
of ozone by the electrical spark, when the appearance of Fremy and Becquerel’s 
able researches induced me for the moment to lay aside the inquiry. The publica- 
tion of Baumert’s memoir led me subsequently to resume it, as his results were not 
in accordance with those which I had previously arrived at. But the method pro- 
posed by that physicist to determine whether ozone is an oxide of hydrogen, or 
oxygen in an allotropic condition, appeared to be so well suited to the purpose, that 
* Memoirs of the Chemical Society, vol. ii. p. 395. f Poggendorff’s Annalen, Band Ixxxix. S. 39. 
t Annales de Chimie, 3^“® serie, xxxv. p. 62. 
§ For a very complete account of all that is known on this subject, see the Article “ Ozon ” in the Hand- 
worterbuch der Chemie, Band v. S. 835 (Braunschweig, 1853). 
