Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.
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case do I allow more than ten cups or elements to be thus em- ployed in the applied current, and but very seldom that number. For safety, as well as for toning- up, the direction of the current should be reversed suddenly, as by the current changer, say every fifteen seconds, and then quite suspended after each min- ute, for at least a few seconds. The seance may occupy ten or fifteen minutes, but the time of the actual working of the cur- rent in all should never exceed from two to five minutes. 1. Seeing. — The normal action of electricity on the organs of sight, i. e., in health, is varied according to its form and application. If static electricity is applied by sparks drawn from the surface of the closed eyelids, there is produced not only the redness of the skin, showing increased circulation there, but the person probably sees faint luminous flashes, or sparks; and this, if not too far prolonged, is followed by an increased functional capability of the whole eye. These sparks should be so graduated in their length as to be bearable, and their succession not continued more than a minute at a time. If we employ electro-magnetism, the superficial portions of the eye respond to its effects, while the retina appears to be but very little reached by it; at least the author has never known the luminous flash or spark to be produced by it. If the mag- neto-electric currents are employed as strong as they can be borne, and with the switch of the machine set so as to give only a one-way current, then, if the positive pole is placed over or near the eye, the retina is decidedly affected. If primary gal- vanic currents are directed to the eye or eyes, by placing the small moist sponge electrode over the closed eyelids, and thus upon the eyeball, then the moderate, constant, and steady cur- rent produces no other sensible effect than a slight prickling in the skin of the eyelids; but if now the current is interrupted, reversed, or varied in density, then there is produced a flash of light as often as the interruption, reversion, or other variation is repeated. This is no actual development of electric light, as might by some be supposed, but merely an instantaneous in- creased action of the retina. The third nerve, if involved in any lesion, arising as it does from above the bifurcation, ought