DISPERSION OF "N" RAYS 61 



The radiations of very small wave-length, 

 discovered by M. Schumann, are to a very 

 great extent absorbed by air ; " N " rays are 

 not. This implies the existence of absorption 

 bands between the ultra-violet spectrum and 

 " N " rays. The wave-length of " N " rays 

 increases with their refractive index, contrary 

 to what occurs with luminous radiations. 



If the increase in brilliancy of a small 

 luminous source by the action of " N " rays is 

 to be attributed to a transformation of these 

 radiations into luminous radiations, this trans- 

 formation is in conformity with Stokes' law. 



Registration by Photography of the Action 

 produced by " N " Rays on a small Electric 

 Spark (February 22, 1904). 



Though " N " rays have no intrinsic action 

 on the photographic plate, it is nevertheless 

 possible to utilize photography to reveal their 

 presence and study their action. This object 

 is attained, as I showed as long ago as May 

 ii, 1903, by making a small, luminous source 



