W. Crookes—Radiant Matter. 245 
entirely justify the application of the term borrowed from 
Faraday, that of Radzant Matter. 
Radiant Matter exerts powerful phosphorogenic action where it 
strikes. 
have mentioned that the Radiant Matter within the dark 
space excites luminosity where its velocity is arrested by resid- 
ual gas outside the dark space. But if no residual gas is left, 
the molecules will have their velocity arrested by the sides of 
the glass; and here we come to the first and one of the most 
noteworthy properties of Radiant Matter discharged from the 
negative pole—its power of exciting phosphorescence when it 
strikes against solid matter. The number of bodies which 
My earlier experiments were almost entirely carried on by 
the aid of the phosphorescence which glass takes up when it 
lumin i aie, 
fe ous sulphide of calcium prep ide is exposed to 
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bluish white color. It is, however, much more strongly phos- 
Phorescent to the molecular discharge in a good vacuum, as 
you will see when I pass the discharge through this tube. _ 
Other substances besides English, German, and uranium 
