330 ILLINOIS ACADEMY OF SCIENCE 



Hautefeuille and Chappms^ followed the course of the 

 reaction when the silent discharge was passed through 

 mixtures of oxygen and nitrogen by means of absorp- 

 tion spectra. A series of new bands was observed which 

 was not characteristic of any of the bands of the oxides 

 of nitrogen then known. On passing this new compound 

 into water the water became acid and apparently only 

 ozone w^as left in the gas. This peculiar compound seems 

 to decompose on continued discharge, or slowly on stand- 

 ing, to lower oxides of nitrogen. This decomposition may 

 be readily followed by changes in the absorption spectra. 

 The formula, NsOe was assigned to the compound as a 

 result of analyses which were, however, widely divergent. 

 Warburg and Leithauser^ have also studied this com- 

 pound and have concluded that it is formed by the ad- 

 dition of ozone to nitrogen pentoxide. 



SpiePhas made a very interesting study of the effect 

 of the silent discharge on enclosed oxygen-nitrogen mix- 

 tures. At first there w^as a marked diminution in pres- 

 sure which reached a limiting value. Then all of a sud- 

 den the pressure increased again nearly to the original 

 value. Analysis of the gas at the point of minimum 

 pressure showed the presence of 5-6% by volume of fixed 

 nitrogen calculated as NO. After the reversal the pres- 

 sure remained constant as well as the composition of the 

 gas so long as the temperature remained constant. If 

 the temperature, however, was allowed to rise after re- 

 versal then fluctuations in pressure were observed with 

 corresponding changes in the amounts of oxides of nitro- 

 gen present. This tends to indicate the existence of a 

 delicate electrical equilibrium which is easily distributed 

 as a result of small temperature changes. The gas at 

 the final equilibrium contained about 0.6% NO. At the 

 lower pressures probably considerable amounts of the 

 ozone-nitrogen pentoxide addition product were formed. 

 During the reversal this was decomposed partly to mole- 

 cular nitrogen, partly to nitric oxide and partly to nitro- 

 gen peroxide. This abrupt reversal appears rather 



^Compt. rend. 9S, 80 (1881); 91 1111, 1306 (1882). 



2 Ann. Phys. 23. 204 (1907). 



^ Spiel. Dissertation, Vienna, 1909. 



