OZONE. 299 



their highest states of oxidation, are put into a tube, 

 containing this peroxide of hydrogen, its oxygen is 

 liberated with the rapidity of an explosion, and so mucli 

 heat is excited that the tube becomes red hot. These 

 phenomena, to which we have already referred in 

 noticing catalysis, are by no means satisfactorily ex- 

 plained, and the peculiar bleaching property possessed 

 by the peroxide of hydrogen sufficiently distinguishes 

 it from water. There are few combinations which show 

 more strikingly than this the difference arising from 

 the chemical union of an additional atom of one element. 

 Similar instances are numerous in the range of chemi- 

 cal science ; but scarcely any two exhibit such dissimilar 

 properties. During the ordinary processes of combus- 

 tion, it has been long known that water is formed by 

 the combination of the hydrogen of the burning body 

 with the oxygen of the air. The recent researches of 

 Schonbein have shown that a peculiar body, which has 

 been regarded as a peroxide of hydrogen, to which he 

 has given the name of OZONE, is produced at the same 

 time, and that it is developed in a great many ways, 

 particularly during electrical changes of the atmosphere. 

 Thus we obtain evidence that this remarkable com- 

 pound, which was considered as a chemical curiosity 

 merely, is diffused very generally through nature, and 

 produced under a great variety of circumstances. 

 During the excitation of an electrical machine, or the 

 passage of a galvanic current through water by the 

 oxidation of phosphorus, and probably in many similar 

 processes in particular those of combustion, arid we 

 may therefore infer also of respiration this body is 

 formed. From observations which have been made, it 

 would appear that, during the night, when the activity 

 of plants is not excited by light, they act upon the 

 atmosphere in such a way as to produce this ozone ; and 

 its presence is said to be indicated by its peculiar odour 

 during the early hours of morning. We are not yet 



