I may add that the electric spark has been obtained from both these fishes. It was only a small spark, but in such experiments a small spark is as satisfactory as a large one.
What are the channels by which the electric fluid is transmitted through our bodies?
They are the nerves, which convey from and to the brain a subtle fluid, if it may be so called, just as the arteries and veins convey blood to and from the heart. If any of these nerves be electrified, even after the death of the animal, or after the separation of a limb from the body, muscular movements are induced, and the limb moves as if instinct with life.
Without these nerves we should be unable to feel the severest shock, but they permeate the body so completely, that not a part of the skin can be pricked without a nerve being wounded.
It is by means of these conductors that the will is made to act upon the limbs. The mind, for example, desires the legs to walk, and they do so, the order being transmitted to them through the nerves.
As a rule, we are unconscious of this process. But, when paralysis takes place, and the nerves refuse to perform their functions, the will is absolutely useless, and, however desirous a man may be of walking, he cannot move a step if the nerves of his legs are paralyzed. In cases where the paralysis comes on slowly and in detail, the patient mostly becomes conscious of the part played by the nerves, and feels that his will can to a certain degree rouse the expiring powers of the nerve fluid.
This in its turn is but the conductor for another and infinitely more subtle fluid, of which our space will not allow us to treat, but which forms the connecting link between body and spirit. Perhaps some of my readers may have seen those curious preparations of the human form, when the arteries have been injected with red wax, and the veins with blue wax, and then the fleshy portions dissolved away by chemical means.
The result is a perfect human form, and even to the very tips of the fingers and toes the blood-vessels follow the contour of the body. Did we have means of injecting the nervous system, we should arrive at similar results, except that the nerves would be found infinitely more intricate than the veins and arteries. Thus a human being is a series of human forms, interwoven with each other, and mutually dependent on each other.
It is curious to see how the great discoveries of modern days have but copied Nature.
Take, for example, the network of telegraphic wires which is day by day spreading itself over the surface of the earth, and the parallel will at once be visible. Just as the brain transmits its message to the limbs by means of the nerves, so does the same brain transmit its message through thousands of miles, by utilising the wires which are but the rough and coarse imitations of the wonderful nervous system of the human frame.