170 L.8.C. Proceedings of the Ninth [N.S., XVIII, 
(4) Tt _— explain the phenomena of magnetism in so far as that 
may be an atomic property. 
time, was due partly to cad Kelvin, but Se aaeuty. ‘a aleli 4 ‘6 
ir Josep mson. is m med a sphere i i 
e 
influence of the central attr —— force provided by the sphere. Elec- 
trons in static equilibrium, not r je ving w wage largely fail to account 
for magnetic phenomena, whi “ae on a theo s kind inv olves =“ 
for whi 
rnal ring structure—and would thevsties be expec o show similar 
pater proper = oetccenale aca as the atomic weight (total 
i d u 
of 
netic moment required for a eee atom was also explaine 
y matter built up of the Thom son atoms. In looking at the great com- 
plexity of epee aterial properties which any atom model ought to 
ecount for s hardly surprising | bela cee early synthetic atoms 
should fail ne certain lines s extraordinary that they 
accounted sol so much and this sidioated that research was at least on 
e main 
of this type of coplanar sing a appea sept of explaining the 
simple relationships between poeateal aslo still le ss the extremely com- 
plex spectra and series of Bite which are known by observation. Indeed, 
b oi s s is na 
later oe the starting point of a completely new design in atom 
It is es difficult te account for the ejection of an a particle in 
radioactive change. But above all, the objection to the Thomson atom 
Hes in its failure to account the mass of the stru The whole 
a z ole 
of the nse ed ae sphere is ip smaller even than ot a a single 
on 
“oe no cnn of a is. 
# : 
of the ultimate constituents of matter did me ee ~~ the old dyna- 
mical laws. The ideas were cats al in the extre and were largely 
rejected as curiosities by the average phiveidiat: T shail attempt to show 
ree er how fruitfully these pain ah have ie oped in the last t few 
ars 
Meanwhile me — on the mystery of the atom has continued to 
davelag: slong tw 
e fi 
atomic droll as woes in (a a) s spectra and s —_ ral series an nd in 
i b) X 
g to bui 
fortunately it t is quite impossible to work backwards and to infer from 
the spectra or other phenomena what kind of atom to start with. The 

