PRESIDENT’S ADDRESS—SECTION A. 
y) 
“ 
(oo) 
of the instruments, and processes of electrical research was also first 
given by Clerk Masel: The oldest and most familiar facts of 
Binge science are those of the attraction of electrified bodies and 
of magnets. Faraday pointed out that the action between such 
Ties depends on the kind of substance surrounding them, and 
gave precision to his ideas by his re-discovery of specific inductive 
capacity, and of specific inductive magnetic capacity, or perme- 
ability as we now call it. The question how does a magnet or 
electrically charged body at a point A manage to act or produce 
« force on another magnet or charged body situated somewhere 
away, say at a point B? A similar question was asked by Newton 
long ago with respect to gravitation, and in his letter to Bentley 
he gives an answer which ‘T think worth quoting at length in spite 
ot its being so well known: ‘ You sometimes speak of gravity as 
essential and inherent to matter. Pray do not ascribe that notion 
to me; for the cause of gravity is what I do not pretend to know, 
and therefore would take more time to consider of it.” “It is 
inconceivable that inanimate brute matter should, without the 
mediation of something else which is not material, operate on and 
affect other matter without mutual contact, as it must do if 
gravitation in the sense of Epicurus be Batevelall and inherent in 
it.” ‘That gravity should be innate, inherent, and essential to 
matter, so that one body may act upon anotHer at a distance 
through a vacuum, without the mediation of anything else, by 
and through which their action may be conveyed from one to 
another, is to me so great an absurdity that I believe no man who 
has in philosophical matters a competent faculty of thinking can 
ever fall into it. Gravity must be caused by an agent acting 
constantly according to certain laws ; but whether this agent be 
material or immaterial, I have left’ to the consideration of my 
readers.” 
Since Newton’s time evidence has accumulated. We have first 
of all the phenomenon of the energy of light and heat which reaches 
us from the sun. This energy is a real ‘thing, in fact it can be 
bought and sold, and so I presume must be admitted to exist, 
though similar considerations applied to gold or silver mines might 
not necessarily have supreme weight. The question is, what ‘be- 
comes of this energy between the eae when it leaves the sun and 
the instant when it arrives at the surface of the earth. I premise 
that it is admitted that Newton’s idea of the emanation of particles 
is proved to be in non-accordance with the facts as far as we know 
them, and that light really does take a fixed time—some eight 
minutes to get from the sun to the earth. We must admit, also, 
that the velocity ot light is practically the same between the sun 
and the earth as it is at the earth’s surface, and moreover, 
that it is the same at least as far as Jupiter. Since no 
other differences have been detected in the light coming 
from the other heavenly bodies, except those which we know 
