STATIC SHOCK, OR THE LEYDEN-JAR SPARK.-This method of application is accomplished by first attaching a pair of Leydenjars to the poles of the machine, and connecting their outer covering of tin-foil by a brass rod.

The poles of the machine are then brought into close approximation; because the strength of the shock is modified, (1) by the size of the jars, and (2) by the separation of the poles.

As this method is, at best, a very severe form of application, it is well to begin with very small jars, and to place the poles.

FIGURE 15.-Shock with Leyden-jar discharge.

as nearly in contact as possible (without actually touching each other). They can then be separated at will, as the exigencies of the case seem to demand.

The chains are arranged in a similar manner to that described in the preceding method (direct-spark application).

This method is best applied to the bare skin. The polarity of the electrode is not, to my mind, a matter of much consequence.

I advise you to handle this form of treatment with extreme caution. I have several times accidentally received a moderate static shock, and I can assure you it is not associated with pleasurable sensations.

STATIC INSULATION.-This method has already been described in connection with the administration of the "indirect spark." It is perhaps the most agreeable of all methods of static treat

ment. The patient is simply charged for a variable space of time (three to twenty minutes) with either positive or negative electricity. The pole of the machine is attached to the insulated platform on which the patient sits or stands. The other pole is "grounded" by a brass chain, running to the floor, a water-pipe, or a gas-fixture.

The poles of the machine are as widely separated as possible, before the wheels are set in revolution.

No pain is experienced. The hair becomes erect, unless very much oiled. The patient experiences a peculiar "tingling sensation," with a tendency toward perspiration, if the adminis

tration is long-continued. If you approach the patient too closely, a spark is elicited at the nearest point. This should be avoided, if possible.

Its therapeutical egects will be discussed later.

THE STATIC BREEZE.-This method of administration of static electricity consists in the withdrawal of a static charge from a patient by means of an electrode of metal or wood, which is pointed.

If the breeze be indirectly induced, this electrode is grounded by a chain attached to a gas-pipe, a water-faucet, or placed in contact with a wood floor when the other connections are not easily accessible. The patient is first insulated (in order to retain a charge), and is then connected with one of the poles

of the machine by means of a chain, which he either holds or fastens to the platform upon which he sits. The electrode is then employed.

FIGURE 17.-The indirect static breeze.

When the breeze is directly induced, the insulated stool is connected with one pole of the machine, and the electrode with the other pole.

If the electrode be a metal one, the electricity is drawn rap

idly from the patient at the point which is nearest to the eleetrode, and a sensation resembling that of a breeze is experienced at the spot where the electricity escapes. Single or multiple points may be employed on the electrode.

In either of these methods, when the electrode is composed of wood, the sensation is modified, to a certain extent, by the poor conductivity of the wooden point. Most patients compare the effect of such an application to a "shower of sand" concentrated upon the point of withdrawal of the charge.

When this method is employed about the eye, the wooden ball or wooden point is usually preferable to one of metal.

When application to the head and scalp are deemed requisite, a metal cap studded with points is hung over the head of

FIGURE 19.—The electrical head-bath, a variety of administration of the static breeze.

the patient by a chain, which is grounded. This cap is known as the "umbrella electrode." It should not touch the patient's head or hair, when he is placed beneath it upon the insulated platform. The numerous points of the electrode draw off the electricity through the hair and scalp, which passes from the machine to the patient, and produce a sensation which is particularly pleasant. A "strong wind" is felt permeating the hair and encircling the head.

STATIC INDUCED CURRENT.-To convert a static machine into what, to all practical purposes, may be considered a "Faradaic" instrument, some slight modifications only are required.

The discovery of this method may justly be attributed to the investigations of Professor W. J. Morton, of New York; although Matteucci first devised an instrument which gave shocks by induction simultaneously with the discharge of a

FIGURE 20.-An application of the Leyden-jar shock during the eighteenth century. Copied from an old English work.

Leyden-jar (see Figure 795 of Ganot's work on Physics, by Atkinson).

To produce this form of current, it is necessary to first hang

FIGURE 21.-The static induced current.

a pair of Leyden-jars upon the arms of the machine. The size of the jars employed modifies the strength of the current; hence it is necessary to have jars of different sizes as a part of a static outfit. You now attach the chains or, by preference,