Intelligence and Miscellaneous Articles. 555 



The action of heat upon ozonized oxygen was found to bring 

 about a sensible permanent expansion (i. e. an expansion which was 

 permanent on cooling down to the original temperature). M. Soret 

 heated his gas by means of a spiral of platinum wire maintained at 

 a red heat by an electric current. Furthermore this expansion of 

 the ozonized oxygen was just equal to the volume of oxygen which 

 the same gas could give up to iodide of potassium. 



Caustic potash acts like heat, and not like iodide of potassium or 

 arsenite of soda : thus, it produces an expansion nearly equal to the 

 volume of oxygen which the gas could give to iodide of potassium if 

 it were treated with that reagent. 



The author suggests this explanation of the action of potash upon 

 ozonized oxygen : it first becomes peroxide of potassium by seizing 

 the oxygen given off by the decomposition of ozone, and then the^ 

 peroxide of potassium itself decomposes, and so the expansion is pro- 

 duced. The oxygen freshly given off by peroxide of potassium is libe- 

 rated in a solution; it would therefore dissolve more readily than the 

 rest of the oxygen, or rather would form, as it were, a supersaturated 

 solution ; and so the very slight inequality between the observed ex- 

 pansion of ozonized oxygen on treatment with potash, and the volume 

 of oxygen which the same sample of ozonized oxygen is capable of 

 giving to iodide of potassium, is accounted for. 



The author remarks that his results, which agree with those of 

 Messrs. Andrews and Tait, are capable of explanation by the theory 

 which has been maintained by Weltzien and Von Babo, and which 

 consists in representing the molecule of ozone as consisting of several 

 molecules of oxygen. 



In producing oxidation, i. e. in acting upon iodide of potassium or 

 arsenite of soda, a volume of ozone gives up oxygen to the body 

 which undergoes oxidation, and liberates a volume of inactive oxygen 

 equal to the volume of the original ozone. Thus there is no altera- 

 tion in the volume of the gas, and yet oxygen is absorbed by the re- 

 ducing agent. In being acted upon by heat, the ozone is simply 

 decomposed into ordinary oxygen, and consequently the result is 

 an expansion which is equal to the volume of oxygen capable of 

 being given up to reducing agents. 



M. Soret calls attention to the fact that, until a determination of 

 the density of ozone shall have been made (for which either pure 

 ozone would be required, or some reagent which could absorb both 

 the active and the inactive oxygen set at liberty on the decompo- 

 sition of ozone), we cannot say how many molecules of oxygen go to 

 form one molecule of ozone ; and, after a notice of Messrs. Andrews 

 and Tait's notion that oxygen itself is a compound, concludes with 

 the observation that the theory of M. Clausius, that ozone exists in 

 combination in ordinary oxygen, is tenable if the addition be made 

 that ozone at the moment of its liberation combines with ordinary 

 oxygen. This latter view would involve just the same experimental 

 facts as the former one*, and, according to the author, would still be 

 in harmony with the reasoning employed by M. Clausius. 



* The theory would indeed involve the experimental facts above given, 

 but it would involve further experimental facts which the theory ascribed 

 to Weltzien and Von Babo would not involve. — J. A. W. 



