82 ROYAL SOCIETY OF CANADA 
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curvature © is dynamically given by ae and this is equal to the 
applied force H e v. 
Therefore Hey = or 4. = Ra 
p m H p 
2 
We have already shown that © — Cu 
< m 2 
D T 
From these two equations we obtain v = EN 
p HQ 
e 2 W 
ACID 2) = eee 
m Fate HE) 
Substituting the numerical values of H, E, and Q, it was found 
that in round numbers 
= 
© ss 
and — Wl,” CMS NpDer ROC; 
We thus have obtained the result that the value of = for 
the particles is about 1,000 times as great as the same ratio observed 
for hydrogen on the electrolysis of water. If the charges are the 
same for both cases, the mass of the carriers in the cathode rays is 
only about 1-1000 of the mass of the hydrogen atom. The velocity 
of these particles is very great, approximating to the velocity of light, 
and enormously greater than any velocity of matter before observed 
in physics. 
The theory from which these results are deduced is possibly open 
to some objections, but the values were confirmed by another inde- 
pendent method. 
If the rays are charged particles their path should be altered in 
passing through an electrostatic field. Hertz obtained negative 
results; but J. J. Thomson, by varying the experimental conditions, 
was able to show that the rays are deviated and that the failure of 
Hertz to observe the effect was due to the masking action of the 
conducting gas, through which the particles moved. This electro- 
static deviation supplied him with a simple means of determining the 
velocity and ratio of © of the particles. The rays were made to 
m 
pass between the plates of a charged condenser and were at the same 
time acted on by a magnetic field. The strength and direction of the 
field was so adjusted that there was no deviation of the path of the 
rays. 
