evi Proceedings of the Asiatic Society of Bengal. [N.S., XV, 
any rate now a clearer apprehension. of the nature of the 
problem that awaits solution, than in Tait’s time. The recent 
advances, accordingly, are real, even although every physical 
concept, nay every notion that was formerly regarded as funda- 
mental has had to be re-discussed and no final pronouncement 
is as yet possible on their true nature. 
orce, for instance. Its objectivity was implicitly 
acknowledged, not merely in text books but scientific discus- 
a proper 
investigations it is legitimate to proceed on the postulate of 
physical existence of forces. ‘To say’ (says Larmor) “that 
force is a mere figment of the imagination ..... is to assume 
a scientific attitude that is appropriate for an intelligence that 
surveys the totality of things.” And accordingly, we find 
that the latest form of the Electron Theory, for instance, pro- 
e on the admission, not that we know what force is but 
a we can identify and thus take cognisance of it, objec- 
tively. 
We have, thus, an indication of how our scientific ideas 
are undergoing re-adjustments, and there are many others 
Some of these we shall have to refer to in due course. Broadly 
stated, however, the great general problem of modern Physics, 
as I conceive it, is the i 
and the processes associated with it. This appears to be the 
meaning of the following extract from Sir Joseph Larmor. 
Referring to the title of his paper read at the Congress of 
hematicians at Cambridge in 1912, on the “ Dynamics of 
Rediation,” he says :— 
