454 On the Reflection of Electrical Rays. 



this confirmed by experiment ; and if we bring into C a wire 

 8 throwing a shadow, we find that its shadow is sharp and nar- 

 row in the region illuminated by the direct rays, but broader 

 and ill defined in the surrounding region. This takes place 

 also when 8 is made the anode. We see from this that the 

 difference in breadth of shadow does not depend upon a 

 stronger deflection which 8, apparently neutral but really act- 

 ing as a weak kathode, causes in the reflected rays*. These 

 last are indeed themselves capable of deflection, as we see if, 

 instead of making 8 an anode, we connect it with the earth, or 

 give to it a small portion of the current from the kathode. 



The motions of the shadow of 8 under the influence of a 

 magnet, and with other arrangements the motions of the sur- 

 face F under similar influence, show that the reflected rays 

 are deflected, as far as one can observe, in the same way as 

 the direct kathode-rays would be if their course were the same 

 as that of the reflected rays. 



If r be placed equatorial ly above a horseshoe magnet of 

 suitable strength, the direct kathode-rays before reaching C 

 are compressed against the upper or under wall of r, and the 

 phosphorescent surface (</>) produced by the direct rays disap- 

 pears ; but the feebly illuminated region remains, occupying 

 now the position of the surface : this corresponds exactly to 

 Wiedemann's surface F; its production here is due to the dif- 

 fuse rays which issue from the portions of the straight tube r 

 struck by the magnetized rays. The further the terminal point 

 of the direct rays is forced towards C by the action of the mag- 

 net, the less luminous does the surface F become, since then a 

 continually smaller portion of r is able to reflect rays. 



On the whole, the foregoing series of experiments leads to 

 the following result, which I propose to describe more fully in 

 a further communication: — A pencil of kathode-rays does not 

 end (at any rate under the conditions suitable for producing 

 phosphorescence) where it strikes upon a solid wall, but elec- 

 tric rays radiate in all directions through the space occupied 

 by the gas from each point of the wall struck by the direct 

 rays. These rays may be called reflected rays. Any solid 

 wall, no matter what its properties are, may serve as reflecting 

 surface. It is a matter of indifference whether it is capable 

 of becoming phosphorescent or not, whether it consists of a 

 conductor or of an insulator. The reflection is diffuse, equally 

 whether the reflecting surface is dead or as smoothly polished 

 as possible. An anode apparently reflects the kathode-rays, 

 the same as a neutral conducting surface or an insulator. The 

 reflected rays, like the direct kathode-rays, have the property 

 * ' A uew Form of Electrical .Repulsion.' p. 124. 



