ey de eee, Lr ee 
W. Crookes—Radiant Matter. 259 
atmospheric pressure forces it in, and now it melts. A hole is 
perforated in the middle, the air rushes in, and the experiment 
Is at an end. 
I can render this focal heat more evident if I allow it to play 
on a piece of metal. This bulb (fig. 15) is furnished with a 
15. 
hegative pole in the form of a cup (a). The rays will there- 
ore be projected to a focus on a piece of iridio-platinum (6) 
Supported in the center of the bulb. , 
I first turn on the induction-coil slightly, so as not to bring 
out its full power. The focus is now playing on the metal. 
raising it to a white-heat. I bring a small magnet near, and 
you see I can deflect the focus of heat just as I did the lumin- 
ous focus in the other tube. By shifting the magnet I can 
drive the focus up and down, or draw it completely away from 
the metal, and leave it non-luminous. I with raw the magnet, 
and let the molecules have full play again; the metal is now 
white-hot. I increase the intensity of the spark. The neg 
platinum glows with almost insupportable brilliancy, and at 
last melts. 
The Chemistry of Radiant Matter. 
As might be expected, the chemical distinctions between one 
kind of Radiant Matter and another at these high exhaustions 
are difficult to recognize. The physical properties I have been 
elucidating seem to be common to all matter at this low density. 
