in the treatment of anesthetic areas in locomotor ataxia, hysteria, and superficial myalgias.

The connections for the Leyden-jar sparks are as illustrated

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FIG. 5. 1, Shepherd's crook. 2, Ground chain to water pipe. 3, Ball electrode. 4, Ground chain to gas pipe.

in Fig. 5. They are the same as for the indirect spark, with the addition of two Leyden jars which may be of three sizes.

FIG. 6. 1, Shepherd's crook. 2, Ground chain to water pipe. The spark is too severe for use unless in the treatment of lethargic states.

The convective discharges include static electrification, interrupted electrification, the breeze, the spray, the brush discharge, and high potential and high frequency discharges from the vacuum tubes.

Static electrification is illustrated in Fig. 6, and is given as follows:

(1) The patient seated in the chair, the balls are widely separated.

(2) The shepherd's crook extends from the positive or negative pole to the insulated platform, and the other pole is grounded. This modality is administered as a mild sedative. Interrupted electrification is illustrated in Fig. 7. The dif

FIG. 7.

1, Shepherd's crook. 2, Ground chain to water pipe. ference between it and static electrification is the discharging spark-gap. It has a more pronounced effect than static electrification uninterrupted. The noise of the discharging sparkgap, however, is disagreeable to some patients. Static electrification may be interrupted by the operator moving the ball electrode, grounded, past the positive pole.

The static breeze, illustrated in Fig. 8, is administered as follows:

(1) The patient seated, the poles of the machine are widely separated.

(2) The shepherd's crook extends from the positive pole usually either directly to the hands of the patient or to the insulated platform and the other pole is grounded.

(3) The stand is placed with the point electrode near some part of the patient or with the crown electrode over the head as indicated or preferred.

If one of the ground chains is connected to the stand the discharge is intensified. Either the point or crown should be

removed just enough so that the patient will not experience a feeling of warmth and prickling.

This modality is used in the treatment of anemic or some types of nervous headache.

The static spray is illustrated in Fig. 9, and is administered as follows:

(1) The poles of the machine are widely separated.

(2) The patient, insulated, holds the shepherd's crook, con

2

FIG. 8. 1, Shepherd's crook. 2, Point above patient's head. 3. Ground chain to water pipe. 4, Ground chain to gas pipe. 5, Stand for holding point or crown electrode.

necting him to either side of the machine, preferably the positive side.

(3) The negative side is grounded.

(4) The operator then administers the breeze by a to-andfro motion usually of the wire brush or pointed electrode, which is also grounded.

The static spray is a mild peripheral stimulant. It is indicated in some nervous conditions where a general superficial glow or warmth is desired, or when it is desirable to induce an active hyperemia superficially. The operator must take care lest he hold the electrode too close to the patient, when a spark will be discharged often to the annoyance of the patient.

The brush discharge is illustrated in Fig. 10, and the connections are as follows:

(1) The poles of the machine are widely separated.

(2) The positive pole of the machine is connected with the ground.

(3) The shepherd's crook always connects the negative pole of the machine with the patient insulated. If a mild current is desired, as in administering the brush discharge to the ear, the crook is held by the patient and the machine run slowly, or it may rest upon the platform. Otherwise the rod may be held by the patient and the machine run rapidly.

(4) The discharge is administered with a long wooden electrode in the end of which may be inserted various terminals.

FIG. 9. 1, Ground chain to water pipe. 2, Shepherd's crook held by patient. 3, Wire brush electrode. 4, Ground chain to gas pipe.

A metal cylinder about three inches in length is slipped over one end of the electrode and the ground chain is hooked to an eye or held in contact with the cylinder. Care should be taken that the fingers do not extend beyond the cylinder, or an accidental spark may pass to the operator's hands. The hood or cylinder acts as a rheostat or controller as it is moved to or from the terminal end of the brush-discharge stick; the resistance being thus varied. If the wooden electrode is used by the operator without a ground chain, the brush discharge is milder in character.

Various terminals are used, as a wooden ball, a wooden point, a metal ball, a metal brush, a metal point, a small metal ball on a rod of vulcanite about four inches long, a large

metal ball on a vulcanite rod about three inches long. The last four terminals localize the discharge. A glass hood is sometimes slipped over the vulcanite terminal. This sleeve may be straight or slightly curved at the end. It is very serviceable when the operator desires to make application to cavities or depressions.

If the brush-discharge stick electrode be heated or dampened the output is increased because the resistance is less. To dampen the stick is preferable, taking care that it is not made too wet lest sparks pass to the patient. The brush-discharge

3

FIG. 10. 1. Shepherd's crook held by patient. 2. Ground chain to water pipe. 3. Wooden electrode with metal sleeve. 4, Ground chain to gas pipe.

stick is best when made of the white part of maple, white wood or holly.

The English use a metal effleuve, or a Bissièrié brush,-a metal electrode in a sliding glass tube, or with an adjustable spark-gap on the handle.

The brush discharge is indicated where superficial congestion is present. It is also a peripheral stimulant and a counterirritant, antiseptic, and rubefacient. It is especially indicated in the treatment of facial neuralgia, eczema, lupus, ulcerations, acne, herpes, hyperesthesia, ecchymoses, superficial swellings, boils, felons, tonsilitis, swelling following fractures, sprains, and similar conditions.

The high potential currents with vacuum tubes may be obtained directly from a static machine or through a static transformer, of which various types are manufactured. This current may also be obtained from the coil, but from that source it lacks the contractile property which characterizes the static discharges. The current directly from the static