Eyes.—The injurious effect of electric light upon the eyes has been carefully studied by several competent observers. So far as known it has been caused solely by the arc light. The symptoms produced by exposure of the eyes for a considerable period to the electric light may be slight or severe. In the slighter cases we find merely an acute conjunctivitis with a slight central scotoma which passes off within twenty-four to forty-eight hours. The symptoms are those usual in acute conjunctivitis—photophobia, lachrymation, sensation of a foreign body under the lids, discomfort in the eyes, and swelling of the lids. In the more severe cases all these symptoms are increased; the photophobia and lachrymation may be intense. There is sometimes severe pain in the supra-orbital nerve, and occasionally a tendency to somnolence. In these cases we find an intense conjunctivitis with chymosis, a central scotoma which may render the patient for the time practically blind, and on ophthalmoscopic examination a congestion of the vessels of the retina and choroid, a neuro-retinitis, and sometimes even hemorrhages into the retina. There is sometimes peripapillary œdema and infiltration around the optic nerve. The pupil of the eye in these cases is usually much contracted. There is sometimes loss of epithelium from the cornea.
In certain severe cases there is produced in addition to the eye symptoms an erythema of the face. Bresse states that this erythema can be produced on the face, arm, or hand by exposure to the voltaic arc at a distance of thirty to forty centimetres. The blush grows deeper for three or four hours, then remains stationary for a time, and ends in desquamation leaving a very durable pigmentation. The erythema is accompanied by a sensation of smarting.
The strength of the light and the length of time required to produce these effects probably vary somewhat according to the color of the light. Emrys Jones states that he is informed that either excess or defect of current gives a less injurious light than the normal current; the excess gives a more violet, the defect a more orange light. On the other hand, Charcot considered that the harmfulness of the electric light was due at any rate in considerable part to the chemical or violet rays, and Bresse found that when violet rays were added to an electric light as by aluminium it was more injurious than before to animals. What part the brilliancy of the light plays in determining the pathological results is not yet fully settled. The heat, however, does not, as a rule, seem to have much effect unless in extraordinary instances where the cornea is burned.
Muscular Contractions.—Another effect of electricity which is externally visible on the human system is muscular contraction. Slight muscular contractions are produced purposely in many cases in medical treatment therapeutically or for the sake of diagnosis. When the stimuli are sufficiently strong and follow each other with great rapidity, or when a strong continuous current is passed through the muscles, they are brought into a state of continuous contraction or tetanus, and in this condition they will remain for a long period or until the electric stimulus is removed. In cases where a severe electric shock is received as from an electric wire, the muscles which come in contact with the wire immediately contract and remain contracted while the current continues to pass through them. As a result of this we often find that when a severe electric shock has been received through the hands by means of a wire or other conductor the sufferer’s hands are involuntarily closed upon the wire or conductor, and cannot be unclosed by any voluntary effort until the current is stopped. While thus holding the conductor the hands are often very severely burnt. Under these circumstances a strong force is required to remove a person from a charged wire if the current be not turned off, and it can only be done at a considerable risk unless by those expert and provided with special means.
Not only the muscles immediately in contact with the conductor, but nearly all the voluntary muscles of the body may be thus affected by a powerful current. Another effect of this involuntary muscular contraction is the forcible muscular movements produced by the shock. As previously stated, when a sufficiently strong shock occurs, the voluntary muscles of the trunk and limbs may be thrown into sudden contraction in such a manner as to throw the person violently and forcibly on to the ground, or against some object or objects in the neighborhood. In this way one may be propelled several feet, and many varieties of surgical injury may be caused. Rarely the force of the contraction is such as of itself to rupture muscles or tendons, and it might even fracture bones or dislocate joints already predisposed.
Essential or Internal Symptoms.
We pass now to what we may consider the internal or essential conditions of electric shock, leaving the mental or psychical results for examination later.
When a person receives a severe electric shock, the symptoms are usually as follows: In the first place there may be little or nothing except a burn or burns, though usually there is some sensation at the moment of the shock. This may be a simple dizziness, and is often accompanied by the sensation of a brilliant flash of light before the eyes, and sometimes by a sense of impending danger. Usually, however, there is a loss of consciousness more or less complete and more or less lasting according to the severity of the shock and the character and course of the current. In the less severe cases this gradually passes away, and in many cases the patient, although weak and feeling shaken and tired, suffers no further ill effects beyond those of the burns and mechanical injuries. Sometimes there follows a general tremor which may last a few hours or for days, and occasionally a clonic rhythmical spasm of one or more extremities. The loss of consciousness may, however, be accompanied or followed by a condition of collapse, in which the pale face, profuse perspiration, cold extremities, and feeble pulse all suggest the administration of stimulants and restoratives. As a rule, in the stage of unconsciousness the face is reddened and rather cyanotic. The pupils are dilated as a rule and the respiration stertorous or absent; the pulse may be full or feeble, sometimes imperceptible for a time. The unconsciousness sometimes lasts for hours, and all means of stimulation, electricity, artificial respiration, rubbing, have to be applied before the patient can be restored. Sometimes this condition is succeeded by delirium (Moyer). In a certain number of cases the shock is immediately fatal, and in others the patients cannot be recalled from their unconsciousness.
The secondary results of the shock, aside from the injuries, may be very slight or again may be serious and lasting. They are far more apt to be of the first class, and when long or continued motor or sensory changes unconnected with injuries follow, we are justified in suspecting mental or psychical phenomena. One class of secondary results is the motor. In addition to weakness, unsteadiness and tremor of the limbs and trunk, it is not uncommon for the patient to suffer from grand rhythmical movements, at first, perhaps, of all extremities, but soon limited to the extremity or extremities which were most exposed or injured by the current. We have personally seen these movements, and feel convinced that they can be distinguished from most of the ordinary forms of convulsive motions and tremors. The whole limb is moved at once and not separate muscles, and the movement is a large, rhythmical one, slow and co-ordinated, not at all suggestive of tremor. Movements of this character are sometimes seen in so-called functional disease (hysteria and allied conditions). They more nearly resemble the movements seen in some forms of Jacksonian epilepsy than any others known to me as occurring in organic disease, but I believe them in these cases to be always strongly suggestive, if not absolutely significant, of functional affections. A case reported by Dr. Robert, of El Paso, well illustrates this condition. The patient, a male, twenty-eight years old, received a shock through a telephone wire. When seen first, reaction was slowly taking place, the entire muscular system was in clonic convulsions. Temperature 97°; pulse rapid and of low tension; respiration 50; no cerebral symptoms. An hour later the movements were limited to the left upper and the right lower extremities, and there was pain running from the region of the spine down the left arm. Twenty-four hours after the shock, temperature 99.5°; respiration 40; pulse 100. Had slept well, but the movements in the left arm had never ceased. The next day these motions were limited to the muscles of the forearm, and on the fourth day they had wholly ceased. These convulsions consisted in extensive motions of the whole extremity or of muscles or muscle-groups, and not of simple tremor. If the movements were forcibly controlled, severe pain ensued.