368 Literature of Ozone. 



pretation brought forward by Schonbein : that ozone was oxygen, 

 to which in some way was added the elements of water. Nor 

 was this point settled by a more elaborate experiment of the 

 same nature, instituted by Fremy and Beccpierel in 1853, who 

 demonstrated that when a certain volume of oxygen is confined 

 over an aqueous solution of potassium iodide, moist silver or 

 mercury, all of the oxygen undergoes absorption by the reagent, 

 under the influence of a sufficiently prolonged series of electric 

 sparks. 



The first to abandon the theory that hydrogen is a constituent 

 of ozone, was Schonbein himself (1849). He employed air, 

 ozonized as strongly as possible by moist phosphorus, and after- 

 wards dried by passage through a sulphuric acid drying-tube. 

 That water was employed in tho generation of the ozone, was not 

 from Schonbein's point of view an essential element in the prob- 

 lem : it was whether this ozone, after drying, still contained the 

 elements of water or hydrogen. 



Three hundred liters of the desiccated air were passed through 

 a narrow glass tube heated to redness, in order to decompose the 

 ozone, and then through a second sulphuric acid drying-tube. 

 Since the latter, in repeated experiments, showed no increase of 

 weight, Schonbein regarded the absence of hydrogen in ozone as 

 conclusively proven. At the same time he did not accept the 

 views of Marignac and De la Rive, declaring that to him the 

 existence of an allotropic modification of a gaseous body was in- 

 conceivable. 



For a long time, however, the theory that ozone was a com- 

 pound of hydrogen and oxygen prevailed. It derived great 

 weight from the experiments, which had been made by William- 

 son in 1845. He prepared ozone by electrolysis, and to avoid 

 obtaining along with the electrolytic oxygen any hydrogen, used 

 oxide of copper dissolved in sulphuric acid as the electrolyte. 

 The gas was dried over calcium chloride, and then passed over 

 ignited copper turnings into a second drying tube. This uni- 

 formly showed an increase of weight. The copper previous to 

 ignition had been reduced by carbonic oxide, and not by hydro- 

 gen, in order to prevent the possibility of any occluded hydrogen 

 being given up, on ignition, to the stream of ozonized oxygen. 



These views were apparently confirmed by Baumert's experi- 



