Electricity Fr.; Electricität, Ger

Forms of Electrical Force employed in Medical Practice.—Magnetism, static or frictional electricity (franklinism), galvanism, fara-dism (electro-magnetic, magneto-electric).

Static or Frictional Electricity. This is obtained by friction from glass, as in the cylinder or plate, and by induction from the Holtz electrical machine. The last-named instrument is best adapted for medical use. The prime conductor of the electrical machine furnishes positive or vitreous electricity, and the rubber, negative or resinous. Various modes of electrization by static electricity are resorted to:

1.  By sparks. In this mode the part to be acted on is made to receive sparks from the machine in action.

2.  The electric bath. The patient is placed on an insulated stool, and is charged with positive or negative electricity from the prime conductor, or rubber, according as he is in connection with either. Sparks may be drawn from the affected part by presenting the knuckles or a metallic conductor. A sharp, tingling sensation, followed by redness and wheals, is produced by sparks, whether received from the machine or drawn from the body.

3.   By the Leyden-jar. In this method, the electricity is condensed in the Leyden-jar, and the charge is transmitted through the part to be acted on.

Owing chiefly to the physicians of Guy's Hospital, London, and Dr. Charcot and his pupils, Dr. Arthius and Dr. Vigouroux, of Paris, the use of static electricity as a therapeutical agent has been revived and rendered entirely practicable. Dr. Morton, of New York, and the author, simultaneously arrived at a method of using the Holtz electrical machine as a means of stimulating muscular contractions, and as a substitute for the faradic current in cases requiring such treatment. Before describing these manipulations it is necessary to say something regarding the structure of the Holtz machine. Various modifications of the original pattern have been introduced; but the most successful is that of Toepler. There are, however, several excellent machines adapted from the Holtz model to suit the views of mechanical theorists or practical electricians, which may be employed with entire confidence. The author has used with satisfaction a machine the revolving plate of which has a diameter of fourteen inches and the fixed plate of sixteen inches. The power may be furnished by an electric motor, by a water motor or more conveniently by an assistant. In the annexed figure, the arrangement of the Toepler-Holtz is shown. This is the model which the author uses, and is found to be sufficiently powerful for medical purposes. During the winter, when the consultation-room is kept at or about 70° Fahr. by artificial heat, this instrument works with entire satisfaction. In the late spring and summer, for the most part, the atmospherical conditions are such that some means are necessary to preserve the instrument from moisture. This is accomplished by inclosing the machine in a suitable glass case and keeping within it some chloride of calcium to absorb the moisture. An arrangement of this kind is preferred by Dr. Morton, of New York, who uses the original Holtz machine.

Fig. 1. The Toepler-IIoltz Electrical Machine.

The Holtz machine may also be employed to procure the muscular effects, hitherto obtained only from faradic appliances. The current passing between the discharging-rods can be tapped by means of a flexible wire attached to the outer coating of one condenser, and another flexible wire connected with the brass knob or bar which is in communication with the interior of the other condenser. The strength of the current and the rapidity of the interruptions are regulated by the distance between the knobs of the discharging-rods. At every passage of a spark a muscular action takes place. If the knobs are placed very near each other, so rapidly do the sparks pass, that the effect produced is very like that obtained from a mild faradic current. Thus, by an arrangement of the machine which can be done on the instant, the actions, heretofore only obtainable from the faradic machines, are readily procured from the statical electrical instrument. Besides the effectiveness of this method, it has the advantage that it is almost painless. In no other way can strong muscular contractions be induced with so little pain, at least.