608 



Arsenic also destroys dry ozone, but, as it likewise combines with 

 dry oxygen, its separate action on ozone cannot be observed with 

 precision. 



Most of the other metals examined, such as gold, platina, iron, 

 zinc, tin, &c., are without action on dry ozone. 



Iodine, brought into contact with oxygen contracted by the elec- 

 tric discharge, instantly destroys the ozone reactions, and a yellowish 

 solid is formed : no change of volume accompanies this action. 



Peroxide of manganese and oxide of copper have, it is well known, 

 the property of destroying ozone, apparently without limit. The 

 authors have found that these oxides undergo no sensible increase of 

 weight, even after the destruction of 50 or 60 milligrammes of ozone. 

 The same oxides, when brought into contact with oxygen contracted 

 by the spark, restore it to nearly its original volume. 



Hydrogen gas, purified with care, and perfectly dry, was not 

 changed in volume by the action either of the electrical spark, or of 

 the silent discharge. 



A similar negative result was obtained with nitrogen and the silent 

 discharge ; but with the spark a very slight alteration of volume 

 appeared to occur, the cause of which is still under investigation. 



In the experiments now described, the electrical sparks and dis- 

 charge were always obtained from the common friction-machine. 

 The discharge from the induction coil, even when passed through two 

 Leyden jars, produces very insignificant ozone effects. The heat 

 which always accompanies this discharge, and its comparatively feeble 

 tension, sufficiently explain its want of energy. 



All the results recently obtained by the authors fully confirm the 

 former experiments of one of them,* that in no case is water pro- 

 duced by the destruction of ozone, whether prepared by electrolysis 

 or by the electrical discharge. They reserve any further expression 

 of their views as to the true relations which exist between ozone and 

 oxygen, till they shall have an opportunity of laying the results of 

 this inquiry in a more complete form before the Society. 



* Philosophical Transactions for 1856, Part I. 



