ON RADIANT MATTER. 



23 



If, instead of a fiat disk, a hemi-cylinder is used for the negative 

 pole, the matter still radiates normal to its surface. The tube before 

 you (Fig. 8) illustrates this property. It 

 contains, as a negative pole, a hemi-cyl- ^^^- ^' 



inder (a) of polished aluminium. This 

 is connected with a fine copper wire, h, 

 ending at the platinum terminal, c. At 

 the upper end of the tube is another ter- 

 minal, d. The induction-coil is connect- 

 ed so that the hemi-cylinder is negative 

 and the upper pole positive, and when 

 exhausted to a sufficient extent the pro- 

 jection of the molecular rays to a focus 

 is very beautifully shown. The rays of 

 matter being driven from the hemi-cyl- 

 inder in a direction normal to its sur- 

 face, come to a focus and then diverge, 

 tracing their path in brilliant green phos- 

 phorescence on the surface of the glass. 



Instead of receiving the molecular 

 rays on the glass, I will show you another 

 tube in which the focus falls on a phos- 

 phorescent screen. See how brilliantly 

 the lines of discharge shine out, and 

 how intensely the focal point is illumi- 

 nated, lighting up the table. 



Radiant Matter when intercejited 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 intervenes they are obstructed by it, and a shadow 



