On Radiant Matter. 15 



to a focus and then diverge, tracing their path in brilliant 

 green phosphorescence on the surface of the glass. 



FIG. 



Instead of receiving the molecular rays on the glass, I 

 \vill show you another tube in which the focus falls on a 

 phosphorescent screen. See how brilliantly the lines of 

 discharge shine out, and how intensely the focal point is 

 illuminated, lighting up the table. 



Radiant Matter when intercepted by solid matter casts a 



shadow. 



Radiant Matter comes from the pole in straight lines, and 

 does not merely permeate all parts of the tube and fill it with 

 light, as would be the case were the exhaustion less good. 

 Where there is nothing in the way the rays strike the screen 

 and produce phosphorescence, and where solid matter inter- 

 venes they are obstructed by it, and a shadow is thrown on 



