Everyone knows, who knows anything about the subject, that an electric current passing inside of a coil of wire induces an electric current in that wire. Now, if the human brain be taken as a battery, then currents are constantly passing from it to various parts of the body, and the head may be considered in a state of constant electrical excitement, the intensity varying with the character of the thought processes. Now, suppose a coil of wire properly prepared in the shape of a helmet, and 42 fitted about the head of one person, with wires attached and connected with a helmet similarly fitted upon the head of another person at any convenient distance. Every electric current in the one human battery must induce a current in the coil around the head, which current must be transmitted to the other coil. This other coil must then, by the reversed process, induce a current in the brain within helmet No. 2, and that person must receive some cerebral sensation. This cerebral sensation might be a thought, and probably would be, if it turns out to be true that brain force is identical with electricity. In that case, the thought of the one person would have produced a thought in the other person, and there is, if we go as far as this, every reason to believe that it would be the same thought. Thus the problem of thinking at a distance by electricity would be solved.
So much for a curious theory of what might be, if so and so were true; but Professor Bell has not stopped with theories, but has actually begun to put them to the test. Not that he is over-sanguine as to the result, but he believes the experiment worth the making, and that seriously. He has actually had two helmets, such as those described, constructed, and has begun a series of experiments in his laboratory. Thus far, the results have been for the most part negative, but not so much so as to prevent him hoping that more perfect appliances may lead to something more conclusive. It is true that the thought in one brain has produced a sensation in the other, through the two helmets, but what the relation was between the thought and the sensation could not be determined.
MAKING THE DEAF HEAR BY THE USE OF ELECTRICITY.
By quick stages the conversation ran into another channel with new wonders possible in the future. Professor Bell has conceived of a method of making the deaf hear, which is certainly startling. He proposes to do away with ears entirely, and produce the sensations of hearing by direct communication with the brain, through the bones of the head. As a matter of fact, the brains of deaf people are usually in a perfectly healthy condition, and the only thing which prevents them from hearing is some defect in communication with the vibrating air. If their brains could be excited artificially in the same way that the brains of ordinary persons are excited by vibrations communicated through the various chambers and passages of the ear, then the deaf would hear in the same way that other persons do.
It is, of course, a fact, that hearing in every instance is merely an illusion of the senses, a sort of tickling of the brain. This tickling of the brain is ordinarily accomplished by the nerve force passing from the third chamber of the ear to the brain itself. If this nerve force is nothing more or less than ordinary electricity, and if science can train electricity to tickle the brain artificially in the same way and at the same points that the nerves from the ear usually do, then the ordinary sensations of hearing must result, whether the person has ears or not. The problem here is to discover the proper way of tickling the brain. The gentlemen who seat themselves in electrocution chairs have their brains tickled in a way which would not be generally satisfactory.
THERE IS DANGER IN SUCH EXPERIMENTS.
In his desire to bring relief to the deaf—and his whole life has been devoted to that object—Professor Bell has begun a series of remarkable experiments in this line. Some time ago, he determined to study the effects produced upon the brain by turning an electric current into it through the side of the head. With this end in view, he arranged a dynamo machine with a feeble current, giving a varying number of interruptions per second, and attached one of the poles to a wet sponge which he placed in one of his ears.
“I risked one of my ears,” he said simply, “in making this experiment, but I could not risk them both, so I held the second pole of the machine 43 in my hand and turned on the current.”
Fortunately no harm resulted, but immediately Professor Bell experienced the sensation of a pleasant sound whose pitch he was able to vary by increasing or diminishing the number of interruptions in the dynamo machine. His assistant standing beside him could detect no sound at all, so that what Professor Bell heard must have been the effect of the electric current upon his brain. This effect he found could be varied by varying the character of the current. Now he argues that greater variations might be produced in the sounds heard by the brain if the current turned into it were varied in the proper manner. For instance, suppose the current from a long distance telephone to be turned through the head of the deaf mute, a sponge connected with either pole being placed in each ear. Then let some one talk into the telephone in the ordinary way, the infinite variations in the current produced by the voice vibrations being passed into the brain directly. Is it not conceivable that such a variety of brain sensations or tones might then be caused in the head of the deaf mute as to make it possible to establish a system of sound signals, so to speak, which would be the equivalent of ordinary language? Indeed, is it not possible that the deaf mute might actually hear spoken words?
Professor Bell’s experiments upon himself have been so encouraging as to make him disposed to try more complete experiments in the same line upon persons who have lost all sense of hearing, and who would doubtless be willing to take the inevitable risk for the sake of the great blessing which a successful issue would bring to them.