Page:Popular Science Monthly Volume 2.djvu/558

538 both on the contractility of the vessels, and the composition of the humors.

In cases of paralysis, more than any others, electricity displays all its healing power. Paralysis occurs whenever the motor nerves are separated from the nervous centres by any injuring cause, or by any modification of texture impairing their sensitiveness. With a destroyed nerve, paralysis is incurable, but, in case of its disease only, its functions can almost always be restored by electric treatment. As there is always some degree of muscular atrophy in the case, electricity is directed upon the nerves and the muscles at once, and the battery and the induction current usually employed together. As a rule, the first modifies the general nutrition, and restores nervous excitability, while the last stimulates the contractile power of the muscular fibres. The difference of action between the two kinds of currents is clear in certain paralyses, in which the muscles show no contraction under induction-currents, while under the influence of constant currents they contract better than the uninjured muscles. Experiments made some years ago in Robin's laboratory, on the bodies of criminals executed, proved that, after death, muscular contraction can still be produced by Volta's currents, though Faraday's current has no such effect.

When the motor nerves are in a state of morbid excitement, they compel either muscular contractions that are lasting, as tonic spasms, or intermittent ones. The different motor nerves most commonly excited are the facial nerves, the nervous branches of the forearm or the fingers, which are affected in "writer's cramp," and the branches of the spinal nerve, whose irritation occasions tic-douloureux, chronic wryneck, etc. Now, electricity cures, or at least noticeably benefits these different morbid states, and exerts the like influence over neuralgic and neuritic affections, wherever these disorders are not the symptoms of other deeper maladies. Currents restore the normal activity of nutrition in the diseased nerves, and the corresponding muscles; they act on rheumatism, too, in the most beneficial way, modifying the local circulation, quieting the pain, and stimulating reflex phenomena, which are followed by muscular contractions. Erb, Remak, Hiffelsheim, and Onimus, have proved beyond question this salutary action on swellings of the joints, either in acute or chronic cases.

The discoveries respecting the influence of electricity over the spinal marrow have been used with advantage in the treatment of such disorders as arise from unduly-excited activity in this organ, such as chorea, St. Vitus's dance, hysteria, and other nervous convulsions, more or less similar. We cite two instances of this sort published by Dr. Onimus, giving an idea of the mode of applying the current in such cases. A child, twelve years old, was seized with a frightful attack. Every five or six minutes it lost consciousness, rolled on the ground, its eyes turned upward, then grew so rigid that none