He chose for his subject electricity.
Nothing could have pleased me better, for Gaston had made the subject interesting, and father had taught me that to this power we were indebted for the motion of our air boat and sleigh, for our fire and light.
To give more than a brief account of Bertrand's address is impossible; to illustrate and explain his experiments alone would require a volume. He made his spoken words into raised signs on sheets of metal, so that a blind man knowing our electrical signs might have read them by touch. He caused us to hear laughter, speech and song that were produced a thousand miles away, and he let us hear the living voices of great men and women who had been dead to us for a thousand years. He concentrated heat so that he could melt steel in a few minutes; he caused his dynamos to give off a gentle warmth that would keep a room at a certain temperature, or that would just simmer some article of food without, making it boil. He concentrated light and diffused it, threw heat rays to a distance, and lit inflamable substances. He put an electric wire round a log of wood eighteen inches in diameter, and cut through it in a few seconds. He allowed us surgical instruments that could be made to perform operations with incredible speed. He decomposed water and made water from the air around us. He performed feats in chemistry with the aid of what appeared to be a plaything in his hands. At a signal from the lecturer the room was instantly darkened, and now commenced a series of wonderful displays. The Aurora Borealis, the rainbow, the primary colors, the lines telling of what substances were being consumed or heated behind the lights given forth, the polarisation and depolarisation of light, photography. All these came and went with amazing swiftness. It took me many months to understand a tithe of what he did with electricity, and yet I found that he had not mentioned a tithe of the uses to which it is put upon our planet.
Bertrand claimed for electricity something more than a first place amongst the forces of nature. Said he:—'We have not to regard wind as one force, water as another, heat and light as two more forces. We have rather to regard electricity as the one great force, and all the rest of the so called forces of nature as various manifestations of and modifications of that one force.The sun is the central dynamo of our system. All the positive forms of electricity come from him. The pull and the push of the positive and negative forms cause rotation and orbital movement in the planets. There is no such force as gravitation: the planets are held in their respective relationship to each other and to the central sun, the satellites to their planets, our sun to his neighbours, and the stellar systems to each other by a force that acts instantaneously and simultaneously in all parts: that force is electricity. From a distance great enough what we call the universe