NEW ACTION PRODUCED BY " N" RAYS 29 



its former brightness. These actions do not 

 appear instantaneous. 



I have generalized the former experiments 

 by employing, instead of a wire heated by an 

 electric current, a sheet of platinum o'i mm. 

 thick, inclined at 45 on the horizontal plane, 

 partially heated to a dark red by a small gas 

 flame placed underneath. A horizontal pencil 

 of " N " rays, concentrated by a lens, was made 

 to impinge on the under face of the sheet, so as 

 to produce a focus at the heated spot ; on the 

 upper face the incandescent patch was observed 

 without interposing ground glass. The varia- 

 tions in brightness are exactly analogous to 

 those of the wire. When observing, through 

 ground glass, the intensity of illumination of 

 the bottom face of the sheet, due to the rays 

 and the flame together, quite similar variations 

 are found. Further, the same results are ob- 

 tained if, instead of making the rays fall on the 

 lower face, or the side on which the flame acts 

 directly, they are directed upon the upper face. 



The different effects produced by " N " rays, 

 viz. their action on a spark or flame, and on 

 phosphorescent or incandescent bodies, would 



