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—­gross matter—­fades away.  To the three states in which we have always known it, the solid, the liquid, and the gaseous, we must add a fourth, the ethereal—­the state of matter which Sir Oliver Lodge thinks borders on, or is identical with, what we call the spiritual, and which affords the key to all the occult phenomena of life and mind.

As we have said, no human eye has ever seen, or will see, an atom; only the mind’s eye, or the imagination, sees atoms and molecules, yet the atomic theory of matter rests upon the sure foundation of experimental science.  Both the chemist and the physicist are as convinced of the existence of these atoms as they are of the objects we see and touch.  The theory “is a necessity to explain the experimental facts of chemical composition.”  “Through metaphysics first,” says Soddy, “then through alchemy and chemistry, through physical and astronomical spectroscopy, lastly through radio-activity, science has slowly groped its way to the atom.”  The physicists make definite statements about these hypothetical bodies all based upon definite chemical phenomena.  Thus Clerk Maxwell assumes that they are spherical, that the spheres are hard and elastic like billiard-balls, that they collide and glance off from one another in the same way, that is, that they collide at their surfaces and not at their centres.