e profound
mysteries of science. Of the nature of the change that takes place, I
say, we can form no image. Chemical force is selective; it is not
promiscuous and indiscriminate like gravity, but specific and
individual. Nearly all the elements have their preferences and they will
choose no other. Oxygen comes the nearest to being a free lover among
the elements, but its power of choice is limited.

Science conceives of all matter as grained or discrete, like a bag of
shot, or a pile of sand. Matter does not occupy space continuously, not
even in the hardest substances, such as the diamond; there is space,
molecular space, between the particles. A rifle bullet whizzing past is
no more a continuous body than is a flock of birds wheeling and swooping
in the air. Air spaces separate the birds, and molecular spaces separate
the molecules of the bullet. Of course it is unthinkable that
indivisible particles of matter can occupy space and have dimensions.
But science goes upon this hypothesis, and the hypothesis proves itself.

After we have reached the point of the utmost divisibility of matter in
the atom, we are called upon to go still further and divide the
indivisible. The electrons, of which the atom is composed, are one
hundred thousand times smaller, and two thousand times lighter than the
smallest particle hitherto recognized, namely, the hydrogen atom. A
French physicist conceives of the electrons as rushing about in the
interior of the atom like swarms of gnats whirling about in the dome of
a cathedral. The smallest particle of dust that we can recognize in the
air is millions of times larger than the atom, and millions of millions
of times larger than the electron. Yet science avers that the
manifestations of energy which we call light, radiant heat, magnetism,
and electricity, all come from the activities of the electrons. Sir J.
J. Thomson conceives of a free electron as dashing about from one atom
to another at a speed so great as to change its location forty million
times a second. In the electron we have matter dematerialized; the
electron is not a material particle. Hence the step to the electric
constitution of matter is an easy one. In the last analysis we have pure
disembodied energy. "With many of the feelings of an air-man," says
Soddy, "who has left behind for the first time the solid ground beneath
him," we make this plunge into the demonstrable verities of the newest
physics; matter in the old sense