W. Crookes—Radiant Matter. 249 
absorption of the last traces of vapor by the potash, and I 
must pass on to the next subject. 
Radiant Matter proceeds in straight lines, 
The Radiant Matter, whose impact on the glass causes an 
evolution of light, absolutely refuses to turn a corner. Here 
is a V-shaped tube, a pole being at each extremity. The pole 
at the right side being negative, you see that the whole of 
the right arm is flooded with green light, but at the bottom it 
stops sharply and will not turn the corner to get into the left 
side. When I reverse the current and make the left pole 
negative, the green changes to the left side, always following 
the negative pole and leaving the positive side with scarcely 
any luminosity. 
In the ordinary phenomena exhibited by vacuum tubes— 
phenomena with which we are all familiar—it is customary, in 
order to bring out the striking contrasts of color, to bend the 
stratifications—disappear entirely. No cloud or fog whatever 
is seen in the body of the tube, and with such a vacuum as I 
his, then, is the kind of phenomenon we get in ipo! 
exhaustions. I will now try the same experiment with a bul 
(B) that is very highly exhausted, and as before, will make 
