[shaver] 



ABSORPTION SPECTRUM OF OXYGEN 



13 



absorbing gas in the tube was approximately one atmosphere. The 

 flow of gas through the ozonizer was started some time before an 

 exposure was made, so as to permit the oncoming gas to sweep out 

 the air from the absorption tube. The percentage of ozone in the 

 mixture in all cases was very small, probably much less than the 

 1 per cent, mixture used by Professors Fowler and Strutt. The 

 absorption spectrum, when photographed, showed a number of faint 

 symmetrical bands about 7 A.U. in width in the region extending 

 from the wave-length X = 2704 Â.U. to the wave-length X = 2455 Â.U. 

 while below this region there was only partial absorption due to the 

 small percentage of ozone used. A comparison spectrum of the 

 absorption due to oxygen at 140 atmospheres was taken and it was 

 found that the bands did not correspond, This is quite evident from 

 Plate I, Fig. 5, which in reproduction (a) gives the oxygen absorption 

 bands, while (b) shows the ozone bands, with the mercury arc shown 

 in (c) as a wave-length standard. The wave-lengths of the ozone 

 bands were measured and the results are given in Table V, from which 

 it will be seen that they do not correspond to the ultraviolet absorption 

 bands found either with liquid or gaseous oxygen. These experiments 

 conclusively showed that the ultraviolet bands obtained in the 

 absorption spectrum of liquid and gaseous oxygen must have been 

 due to oxygen itself, and not to the nitrogen impurity or small per- 

 centage of ozone present. 



V. Summary 



(1) The absorption spectrum of oxygen, both liquid and gaseous, 

 between the wave-lengths X = 7000 A.U. and X = 2150 A.U. has been 

 examined. 



(2) In the visible region eight absorption bands were noted in the 

 case of liquid oxygen and seven with gaseous oxygen. 



