AND SCHONBEIN 101 



ozonized oxygen to its ordinary condition. More- 

 over it would be strange if heat, which as a rule 

 increases the chemical activity of oxygen, should 

 produce the opposite effect on ozone. 6. In dry air 

 phosphorus has not the power to produce ozone in 

 appreciable quantities, but it forms it the more 

 abundantly, the more moisture is present. 



With regard to the formation of ozone by means of 

 phosphorus, it appears to me that this fact is equally 

 remarkable whether we assume the former to be 

 modified oxygen or peroxide of hydrogen, for finely 

 divided phosphorus shaken up with an atmosphere of 

 ozone immediately destroys the latter. The forma- 

 tion of ozone in the presence of phosphorus must 

 strike us as equally strange whether we assume that 

 by means of catalysis modified oxygen or gaseous 

 hydrogen peroxide is formed, for the former should 

 be absorbed by phosphorus just as readily as the 

 latter should lose its active oxygen. I would take 

 this opportunity of drawing your attention to the 

 behaviour of ozone towards iodine, bromine and 

 chlorine. The compound formed when paper charged 

 with iodine is held in an atmosphere strongly charged 

 with ozone, is so like chlorine, that it shows almost 

 all the properties of the latter. It is not an acid, but 

 on treatment with water it is converted into iodic 

 acid and iodine. Similarly bromine and chlorine 

 water, which have absorbed large quantities of ozone, 

 are by no means acid, i.e., they do not contain chloric 

 or bromic acid. The same substance which ozone 

 forms with iodine seems also to result when strips 



