ANODE RAYS AND THEIR SPECTRA. 127 
rays (cathode rays), but also atomic rays. If one examines these 
atomic rays in a magnetic field one finds that they do not carry as 
expected a negative charge, but a positive charge. As these rays come 
from the anode and have, against all expectation, just as the K, rays, 
a positive charge, I called them A, rays. 
Thus we see that positive rays pass through the electrode a whether 
it is acting as cathode or as anode. In the first case these rays are 
canal rays; in the second case A, rays. 
Without supposing that here there is some radio-active process going 
on, we must conclude that these A. rays obtain their velocities as nega- 
tive ions. 
If afterwards they show a positive charge they must have dissociated 
negative electrons on their way. So the hypothesis seems permissible 
that in gases at low pressures material particles, having a certain 
velocity, dissociate negative electrons. This hypothesis of the origin 
2 OV 
Fic. 3. 
of K, and A, rays is in accordance with the results of Willy Wien, 
for it will be remembered that he found that a bundle of uncharged 
canal rays becomes positively charged during their passage. 
The following diagram shows all the rays carrying electric charges 
in a vacuum-tube (fig. 4) :— 
Mo<|>e@5 Mo<\>eE 
Mote >eE’ , 
M 
"SoM tae 
K A 
Fic. 4. 
A represents a pefforated anode. 
K ss cathode. 
Black points E represent electrons. 
Circles M represent positively charged particles. 
The rays leaving the anode seem to be identical with those leaving 
the cathode, if one supposes that the rays at the anode have their origin 
at a gas-cathode situated just in front of the surface of the anode. 
In regard to the spectra of the anode rays it may be mentioned that 
the alkali rays show about the same spectrum as in the electric arc, 
a spectrum which consists of series. The spectrum which the anode 
rays from the metals of the alkaline earths emit is much simpler than 
