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XIX. Further Observations on the Allotropic Modifications of 

 Oxygen, and on the Compound Nature of Chlorine, Bromine, i^c. 

 By Professor Schonbein*. 



My dear Faraday, 



THESE last six months I have been rather busily working 

 on oxygen, aiad flatter myself not to have quite in vain 

 maltreated my favourite ; for I think I can now prove the cor- 

 rectness of that old idea of mine, according to which there are 

 two kinds or allotropic modifications of active oxygen, standing 

 to each other in the relation of + to — , i. e. that there is a 

 positively-active and a negatively-active oxygen, — an ozone andan 

 antozone, which on being brought together neutralize each other 

 into common or inactive oxygen, according to the equation 

 0-f-0 = O. 



The space allotted to a letter being so small, I cannot enter 

 into the details of my late researches, and must confine myself 

 to some general statements, which I hope, however, will give 

 you a clear notion of the nature of my recent doings. Having 

 written a paper on the subject, that will before long be published 

 in the Transactions of the Academy of Munich, I shall not fail 

 to send it to you as soon as possible. 



Ozonized oxygen, as produced from common oxygen by the 

 electrical spark or phosphorus, is identical with that contained 

 in a number of oxy-compounds, the principal ones of which are 

 the oxides of the precious metals, the peroxides of manganese, 

 lead, cobalt, nickel and bismuth, — permanganic, chromic and va- 

 nadic acids ; and even the peroxides of iron and copper may be 

 numbered amongst them. 



The whole of the oxygen of the oxides of the precious metals 

 exists in the ozonic state, whilst in the rest of the oxy-compounds 

 named, only part of their oxygen is in that condition. I call 

 that oxygen negatively- active, or ozone par excellence, and give 

 it the sign on account of its electromotive bearing. Though 

 generally disinclined to coin new terms, I think it convenient to 

 denominate the whole class of the oxy-compounds containing 

 "ozonides." There is another less numerous series of oxy- 

 compounds in which ^part of their oxygen exists in an opposite 

 active state, i. e. as or antozone, wherefore I have christened 

 them " antozonidcs." This class is composed of the peroxides 

 of hydrogen, barium, strontium, and the rest of the alkaline 

 metals ; and on this occasion I must not omit to add, that what 

 I have hitherto called ozonized o\\ of turpentine, sether, &c., 

 contain their active oxygen in the state, and belong thex'efore 

 to the class of the " antozonides." 



* Communicated bv Professor Faraday. 



