26 21ie Production of Peroxide of Hydrogen. 



time in dilute condition without great loss of either,* but also 

 that the amount of hydrogen, peroxide in the ozonized gas, bears 

 a not inconsiderable proportion to that of the ozone itself. In 

 fact, neglecting for a moment the minute amounts of hydrogen 

 peroxide that are held back by the wash-waters, the ratio of- the 

 hydrogen peroxide to the ozone in the ozonized air exceeds one to 

 three. 



The amounts of hydrogen peroxide held back by the wash- 

 Avaters Avere as follows : — The bulb F, containing 47 cc of water, 

 after evaporation to two-thirds its original volume, in order to 

 expel any dissolved ozone, Avas found to contain 0.2 mgrm. 

 lI^O^j. The bulb G, containing 20 cc. Avater, after being simi- 

 larly evaporated, gaA^e a reaction corresponding to 0.08 mgrm. 

 H,0,. The bulb R, to 0.01 mgrm. H,0,. The falling ofE in 

 the amount of hydrogen peroxide contained in //, in comparison 

 Avith that in G, is perhaps greater than should be, for the reason 

 that //and / were changed during the experiments, and a much 

 smaller amount of ozonized air ])assed through them than 

 through the two preceding bulbs. But the striking feature in 

 the experiment is, that only 0.3 mgrm. H./)._, in all was absorbed 

 by the Avash-Avaters, the remainder j^^^ssing on in the stream of 

 ozonized air. 



Finally, to determine the truth or falsity of proposition V : — 

 Tliat the aii-, afti-r being deprived of its hydrogen peroxide and 

 ozone, could bring about a decom[)osition of an acidified solution 

 of potassium iodide, — the experiment Avas again repeated Avith 

 the tube W maintained at a temperature of 200°. It Avill be 

 noted that in CA^ry preceding trial at this temperature, a neutral 

 solution of iodide being used, no liberation of iodine occurred. 

 But in this experiment, a decomposition took place correspond- 

 ing to 0.2 mgrm. of ozone. This experiment, therefore, proves 

 that the oxygen contained in a current of air, from which every 

 trace of hydrogen peroxide and ozone has been removed by strono- 

 heating, may produce apparently the ozone reaction, in case the 

 potassium iodide solution used for titration has been acidified. 



■ * This point, in opposition to the statements of Schonbein, has likewise been established by 

 Schcine. Jour, fur Prakt. Chem., LXXVI, p. 130, and Ann. der Chim., CXVI, p. 240. 



