198 ANNUAL OF SCIENTIFIC DISCOVERY. 



la Rive, we have examined, first, the oxidizing properties of the 

 oxygen procured by the decomposition of water by the galvanic pile ; 

 the result of these researches is that the pile cannot be employed to 

 determine the nature of ozone, because the active principle is found 

 only in very small proportion, in the oxygen of the pile. We have, 

 therefore, been obliged to study successively all the methods that can 

 be employed to electrify oxygen. The arc which is formed upon 

 the interruption of the voltaic circuit does not appear to modify the 

 oxygen in the same manner as the ordinary spark, because the eleva- 

 tion of temperature which accompanies it probably destroys that 

 which the electricity might produce ; but according to our observa- 

 tions, this arc may determine the combination of gases among them- 

 selves, acting thus as spongy platinum and as electricity ; under its 

 influence we have combined nitrogen and oxygen directly, to form 

 nitric acid, nitrogen and hydrogen and ammonia, and sulphurous acid 

 and oxygen to form anhydrous sulphuric acid. 



Pure oxygen, enclosed in glass tubes, together with a band of 

 starched and iodized paper, was electrified by means of a series of 

 sparks striking the outer surface of the tube ; the paper began to 

 become blue after the passage of a few sparks. This colorization 

 depends on electrization of the oxygen, and not on the decomposition 

 of the iodide ; for no effect takes place when the iodide is placed in 

 hydrogen, and operated on. This fact, is so much the more remark- 

 able, as the oxygen is electrified without the intervention of metallic 

 wires, and consequently without the presence of particles transported 

 by the electric spark. Oxygen, prepared by the most different 

 modes, acquires a very distinct odor, and strongly marked oxidizing 

 properties when it is subjected to the influence of electricity ; these 

 properties are manifested by oxygen as pure as it is possible to obtain. 

 The oxygen thus electrified loses its oxidizing properties when exposed 

 to iodide of potassium, but regains its odor and chemical activity when 

 again electrified ; this experiment may be repeated indefinitely on the 



same gas. 



All these facts show that the oxidizing power of electrified oxygen 

 is not due to the presence of a foreign body contained in the gas ; 

 when pure and dry oxygen is enclosed in a series of glass tubes and 

 subjected to the action of electric sparks, if after a time we break the 

 extremities of these tubes to ascertain the volume of gas that has 

 become immediately absorbable by alkaline iodide, we shall find that 

 during several hours the modification increases in proportion to the 

 time of electrization, and that afterwards it appears to diminish, 

 probably because the spark destroys 'that which at first it pro- 

 duces. 



The difficulties presented in the preceding experiment induced us to 

 study the deportment of electrified oxygen with certain absorbing bodies, 

 capable of immediately seizing the modified oxygen and of withdraw- 

 ing this gas from the decomposing action of an excess of electricity ; 

 we, therefore, passed a series of electric sparks into small eudiometric 



