Akt. I. — On Ozone. By E. L. J. Ellery, Esq., President 

 of tlie Koyal Society. 



[Read 12th February, 1866.] 



Many years ago Schonbein, of Basle, discovered the 

 peculiar principle which is now known as Ozone ; its chemical 

 and physiological relations have been ably studied by that 

 sagacious philosopher ever since, as well as by Andrews of 

 Belfast, Tait, de la Rive, Becquerel, Baumert, and others, and 

 although much mystery still envelopes the nature of this 

 body and its effects, there is yet a large amount of evidence 

 and experience concerning it, which, as far as I am able, I 

 propose to lay before this Society. The general interest which 

 attaches to ozone is, I conceive, principally due to the belief 

 that it frequently forms a constituent of our atmosphere, and 

 has a special influence in the animal economy, and, although 

 it is questioned that this has been satisfactorily proved, there 

 are few scientific men who venture to deny it. The want of 

 satisfactory or absolute proof is owing, for the most part, to 

 the difficulty of obtaining pure and free ozone in quantities 

 sufficient for analysis and experiment, or in devising tests 

 for its presence, which shall be incapable of being influenced 

 in the same way by any other body as by ozone ; but it will 

 be useful to work as well as possible with the means at our 

 command. I, therefore, propose to consider Ozone that prin- 

 ciple present in our atmosphere which gives the reaction on 

 iodide of starch papers known as ozone tests. For whether 

 the reaction be due to ozone and ozone only, or not, or 

 whether some more or less frequent reactions may not be 

 due to nitric acid or some other highly oxydizing agents, 

 will not matter, since the same physiological effects appear 

 to be the result whenever the reaction happens. Much 

 difference of opinion has at various times been entertained 

 concerning the nature of this body. Schonbein at first con- 

 sidered it to be a peroxyde of hydrogen (HOg ) in the 

 vaporous state. Baumert has recently suggested HO3 as the 



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