
124 NATURE OF THE RADIATIONS 
Distance in mms. 
from the slit Hp 
1 2°91 x 105 
3 ao) a 
5 SOGaay. 
7 Bla 5 
8 3:24 
9 3°41, 
The writer (loc. cit.) showed that the mazimum value of Hp 
for complete deviation of the a rays was 390,000. The results are 
thus in good agreement. Since #, p=— V these results show 
that the values either of V or of = for the projected particles vary 
at different distances from the source. Becquerel considered that 
the rays were homogeneous, and, in order to explain the results, 
has suggested that the charge on the projected particles may 
gradually decrease with the distance traversed, so that the radius 
of curvature of the path steadily increases with the distance from 
the source. It, however, seems more probable that the rays con- 
sist of particles projected with different velocities, and that the 
slower particles are more quickly absorbed in the gas. In conse- 
quence of this, only the swifter particles are present some distance 
from the source. Before any definite conclusion can be reached, it 
will be necessary to determine the actual values of e/m and V for 
different points of the trajectory. 
Becquerel states that the amount of deviation, in a given | 
magnetic field, was the same for the a rays of polonium and of 
; ; mae 
radium. This shows that the value of — V is the same for the 
e 
a rays from the two substances. Since the a rays from polonium 
are far more readily absorbed than the « rays from radium, this 
sun Te 
result would indicate that the value of — is greater for the a par- 
e 
ticles of polonium than of radium. Further experimental evidence 
is required on this important point. 
86. Mass and energy of the « particle. It has been 
pointed out that the a rays from radium and polonium are 
analogous to the Canal rays of Goldstein, for both carry a positive 
