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SCIENCE PROGRESS 



It is seen that, except in one case, a large part of the reaction 

 had resulted in the formation of iodate. The one case in which 

 this compound had not formed was where the ascent had only 

 reached an altitude of &$ kilometres, where the temperature 

 indicated was — 31 "5°. Since the freezing point of the reagent 

 is — 24°, complete solidification had probably not occurred. The 

 fact that, as in the case of all measurements at lower altitudes, 

 there was no iodate formed in this measurement, indicated the 

 absence of oxides of nitrogen, and the formation of iodate in 

 experiments at greater altitudes is due to the reaction of 

 ozone on the solid reagent, as was established in laboratory 

 experiments. 



By considering these results together with those made on 

 ground level at altitudes up to 35 kilometres, the conclusion 

 may be drawn that there is no appreciable amount of hydrogen 

 peroxide in the higher atmosphere, but that there is a consider- 

 able quantity of ozone. 



The mean values of ozone estimated in the measurements 

 made in the Alps were 2*5 x io~' ! in one volume of air at 2*5 

 kilometres altitude, and 47 x io~ 6 parts at 35 kilometres. In 



