As to the question of the real nature of electricity, recent experiments and further knowledge of its properties rather open fresh avenues to new hypotheses than point to the truth of any one special theory. Some identify electricity with energy, some with matter, and some with the subtle all-pervading "ether." At all events it has been computed that in every single cubic foot of ether there are locked up 10,000 foot-tons of energy! The latest researches give well-founded hopes that this inconceivably vast storehouse of power will one day be accessible to man. And herein lies the splendid possibility of a new and mighty successor to the decreasing energy of our coal-fields, with the speedy extinction of which alarmists threaten us. By creating in a room a powerful electrostatic field alternating very rapidly, Professor Nicholas Tesla brought it to such a state that illuminating appliances could be placed anywhere, and kept lighted without being electrically connected with anything! He suspended two sheets of metal, each connected with a terminal of the electric coil, between which an exhausted tube, carried any whither, remained always luminous.

A true flame can now therefore be produced without chemical aid - a flame yielding light and heat without the consumption of material or any chemical process! Further, these and similar experiments on electric radiation, which now advances so brilliantly to the forefront, by Tesla and Crookes, etc., point to the bewildering possibility of telegraphy without wires, without cables, without posts. There is considerable evidence to show that, could the electric ether-waves be obtained sufficiently short, the rays would fall within the limits of visibility, and thus place the final crown of proof on the magnificent experiments of Hertz and others, who would make light an electric phenomenon.

As regards the effect on the human body of alternating currents of very high frequency (which at best have a very doubtful reputation) it has been found that, as the rapidity of the alternation increases, they become, not more, but less dangerous. In fact, Tatum has shown that their fatal effects are nearly inversely proportionate to their frequency. Thus, with currents alternating about 5,000 per second, the current needed to become fatal is about 10 times greater than at the ordinary low frequency of about 120 per second. With still higher frequencies used by Tesla (up to 20,000 per sec.) the currents are incomparably less dangerous than at low frequencies; but still altogether harmless.