Gentlemen,
In our first Lecture we studied the different kinds of electricity employed in medicine, and the construction and management of batteries. I reminded you that we made use of three kinds of electricity; firstly, of friction or static electricity, Franklinism; secondly, of the electricity of chemical action, Voltaism, or Galvanism; and, thirdly, of induced electricity, Faradism:—that there had been certain difficulties in the employment of Franklinism, but that these difficulties no longer existed; that Voltaic electricity was electricity in motion, or current electricity, but that while its current (unless artificially interrupted) was always continuous—flowing, that is, in an unbroken stream—and from the positive to the negative pole, until the battery was exhausted—it by no means followed that it was constant, that is, that it did not vary appreciably in power during application; that only batteries supplying a fairly constant current were fitted for medical use, and that all others should be rejected. We then considered different batteries, both fixed and portable; that while large fixed low tension batteries were unquestionably superior in their therapeutic effects, patients unfortunately were not always movable, and that a portable battery became, therefore, a sine quâ non; that portable batteries might be conveniently divided into two classes, one in which electricity was generated by the elements being immersed in an exciting fluid only during actual use, and being taken out of the fluid immediately after use; and the second that in which no removal of the elements was necessary; that the Voltaic current was graduated into doses by some arrangement determining the number of cells to be employed in each case, but that this method, while practically useful and sufficient, failed to convey an exact idea of a measured and unvarying quantity of electricity; and that it had been contended that by the use of a galvanometer, doses of electricity might be as accurately administered as so many grains or minims of ordinary medicines, but that, perfect as the theory might be, I had personally failed to obtain help in practice from a galvanometer; that next in importance to a method of dosage, was it to be able to instantly change the direction of the current, or to at once turn it “off” or “on,” in addition, of course, to the fundamental requisite of a continuous supply of electricity of sufficient quality and quantity.
We next considered the induced or Faradaic current, so-called, which I reminded you is not a current at all, but a rapid discharge or succession of those momentary shocks, each perfectly distinct in itself, and separated by an appreciable interval of time from its fellows, which Faraday discovered to be generated or induced by a Voltaic current flowing along a wire in other wires parallel to, but separated from, the first wire; that by winding the two wires upon two movable reels and introducing one within the other, not only might these secondary currents be multiplied indefinitely in proportion to the number of spirals of wire, but by introducing or withdrawing the one from within the other an exact method of graduation was afforded us. I pointed out to you that there was no therapeutic distinction between the so-called primary and secondary currents, and I recommended you therefore to use only the currents of the secondary coil. I then showed you the construction of Faradaic instruments, and of instruments combining both Voltaic and Faradaic currents, and our survey was completed by a consideration of the different varieties of conducting wires or cords, and my recommendation of thin gutta-percha covered copper wire as generally superior to any other form. We have to-day to study methods of applying electricity, and to learn how to use the instruments, with the construction and properties, of which I trust you are now familiar; and, Gentlemen, it is well worth your while to have obtained this knowledge, for its possession will not only enable you to readily rectify any faults in the working of your batteries, but the necessity of sending them to the instrument-maker may be often avoided.
We have already studied methods of applying Franklinism.[10]
Voltaization and Faradization may both be applied either generally—as in the different forms of electrical baths—or locally.
A convenient method of applying electricity, when very strict localization is not required, is to insert the feet and hands of the patient, or one foot and one hand, as the case may be, in separate vessels containing tepid salt and water with which the conducting wires of the battery are in contact, the current being allowed to circulate during the time required. Ordinary foot-pails, basins, or jugs, will fulfil every requirement; while thick telegraph wire answers well to connect the battery with the vessels of water, as it is little liable to break and wears well. A variety of the constant current (originated by Dr. Radcliffe) is very readily applied in the way just described, with the addition only of some means of insulating the patient and the accessories, and of a length of ordinary uninsulated copper wire.|Radcliffe’s Positive Charge.| Dr. Radcliffe believes that an administration of positive Voltaic electricity, somewhat analogous to the charge of Franklinic electricity, is frequently beneficial. He insulates the patient and the accessories, and having connected the negative pole with the earth by a wire which he calls a “ground-wire,” he allows the current to pass. With careful insulation the negative electricity passes away by the wire, and while the current circulates the patient continues “charged” with positive electricity. There must be two wires from the negative pole, one to be applied, as well as the positive, to the patient, and the other taken “to earth.” This latter may be conveniently attached to a chandelier or gas-pipe, which always gives a direct metallic conduction to the ground. A perforated vulcanized indiarubber mat, or a sheet of gutta percha, or a glass-legged stool can be employed to insulate the patient and the accessories.
There is another generalized application which has been much advocated, and remarkable statements have been put forth, not only of its curative power in almost every disease, but also of its purely physical and chemical effects—I refer to that by “Electric Baths,” several establishments of which exist in London, but you need not send your patients to them. You can teach them how to take an electric bath in their own bed or bath-room. A bath sufficiently large for the patient to recline in it should be insulated by glass supports (four stout tumblers will do very well), and filled with water at a temperature of 95 to 100 degrees. A metallic plate in connection with one pole may be inserted at the head, and a second plate in connection with the other pole at the foot of the bath. The patient should be protected from direct contact with either plate by sitting upon a wooden framework. With a sufficiently powerful current, a portion of the electricity will pass through the body of the patient reclining thus between the poles. Another method is to connect the water with one pole, and for the patient to grasp in his unimmersed hands a copper bar covered with wet flannel, and in connection with the second pole of the battery; or a conductor from this second pole may be held almost, but not quite, in contact with any part of the body immersed in the water. Either the Voltaic or Faradaic current may be used. Ordinary water with the Faradaic current, but salt and water, or acidulated water, with the Voltaic.
Another more generalized application is that introduced by Beard and Rockwell, under the name of “General Faradization.” The patient sits with his naked feet upon a sheet of copper connected with one pole, while the other pole is connected by a moistened sponge with the left hand of the operator, who passes his disengaged hand, slightly moistened, over the muscles of the patient, and sometimes over his whole body. The current, I need hardly say, passes through the body of the operator before it reaches the patient, and the sensation he feels is his chief guide to its graduation.
Another general application is the “Centralized Galvanization” of the same authors, in which their object is to bring the whole central nervous system under the influence of the Voltaic current.
They place one pole—usually the negative—at the epigastrium and pass a large moistened sponge from the positive pole over the forehead and top of the head, along the inner border of the sterno-mastoid, from the stylo-mastoid fossa to the sternum, and down the entire length of the spine, from the nape of the neck to the sacrum. The brain, sympathetic and spinal cord, and the pneumogastric nerves are thus submitted to the influence of the current.
But the great majority of cases require—not a generalized, but a strictly localized application, and for the fundamental principles of all methods of localized electrization we are indebted to the late Dr. Duchenne (the “father of electro-therapeutics”), for before him no one had attempted any local application of electricity that could properly be so called. Indeed, to Duchenne may be fairly ascribed the very birth of medical electricity as a branch of therapeutics, and in the true and kindly words of the Lancet, when announcing his death:—“No field of work was ever seized upon with more eagerness; ever cultivated with more earnestness; or perhaps ever made to yield a better harvest than that which the discovery of induced electricity placed at the disposal of the man whose genius was the first to recognize, and his talents to secure, the opportunity it afforded. Taking his work at its lowest estimate, he was a man to whom medical science owes a large debt of gratitude, and whose memory deserves a warm tribute of regard.” Duchenne’s two test experiments, demonstrating the fundamental principles of his method, I will now repeat upon the posterior surface of my left forearm. I propose to arrest Faradism in the skin, without allowing it to stimulate the subjacent muscles. To do this it is necessary for the skin to be quite dry—moisture, as you know, being a conductor of electricity—and to make sure of sufficient dryness, I sprinkle the skin with a little starch powder. I now apply to the dry skin the dry metallic conductors of an induction instrument in action. I am afraid you cannot see, Gentlemen, the small sparks produced as the two electricities combine upon the cutaneous surface, or hear the slight crackling sound produced, but you observe no muscular contraction, and what I feel is a superficial and evidently cutaneous sensation. I now replace the dry conductors by well-moistened sponges. You observe that I have not altered the power of the current, but that there is energetic contraction of the extensor muscles. This is quite involuntary, and is due to the electric irritation of the branches of the motor nerves.
It follows from these experiments that we may, at pleasure, arrest electricity in the skin, and that without puncture or incision we may make the current traverse the skin, and concentrate its action upon subcutaneous organs. It was at one time objected that the muscular contraction was the result—not of irritation limited to the muscle or its motor nerves—but of reflex action; but Duchenne demolished this objection by a vivisection. Having removed the skin from the face of a living rabbit—to whom chloroform had been administered—he divided the facial nerve of one side only, in order that the muscles supplied by it might be cut off from all connection with the cord. He then applied electric excitation to each muscle of the face, alternately, on the two sides. The muscles contracted separately and equally on both sides. He then destroyed the brain of the same animal, in order to place the cord in a condition favourable to the production of reflex action, and again excited the muscles as before. The results were absolutely the same.[11]
Muscular electrization may be produced either—as I have just shown you—by placing the conductors upon the muscle itself, a procedure termed direct or intra-muscular electrization, or by exciting only the motor nerve trunk, which is termed indirect, or extra-muscular electrization, and which we shall consider presently.
Fig. 13. Cylindrical Sponge-holder.
For direct excitation of the larger muscles it is convenient to use well-moistened sponges, contained in cylinders of different sizes, or metallic disks, covered with wet leather and having conveniently shaped handles. A useful size of cylinder is one such as this (see Fig. 13), having a depth of about 1 1/2 by 1 1/8 inches, which allows the sponge to fairly fill it, while in such forms as this—6 inches by 1—when the sponge is inserted the lower three-fourths of the cylinder is empty, and the conduction of the current liable to become imperfect. Such a cylinder as this, without any insulating handle at all, is worse than useless, and is a still persisting relic of the barbarous time when the patient was invariably electrized by causing him to hold the conductors one in each hand, a proceeding extremely dangerous in certain pathological conditions, and in other cases not likely to be of benefit to him. The insulating handles should be well hollowed out, that they may be used, lying comfortably between the fingers, when holding two in the same hand. The disk rheophore (see Fig. 14), a metallic button covered with wash-leather, is extremely useful; it has the advantage over the sponge of allowing firm pressure to be made without the inconvenience of water being squeezed out, while by using its edge it may be made to answer in the majority of cases for a pointed conductor, which is fitted chiefly for application to very small muscles, such as the interossei and some of those of the face. The wire is attached to the conductor by being screwed into the socket (see a′, Fig. 14). A conducting cord is very apt to get frayed at the point of juncture, and that the wire which I recommend is not open to this objection is not the least of its advantages.|Direct Electrization.| In direct electrization the rheophores should be firmly pressed down upon all points of the surface of the muscle, that all of its fasciculi may be equally electrized. With the Faradaic current it is convenient to apply the rheophores, held in the same hand (see Fig. 15), for from twenty to thirty seconds, to every part of the surface of the muscle, or group of muscles, promenading them as nearly as may be in lines from the origin to the insertion of the muscles. If the rheophores are not held in the same hand care should be taken to keep them near to one another, for the tension or penetrating power of Faradism is so great, that without this precaution there will be liability to excite reflex action. With the interrupted Voltaic current this liability does not exist, and a better plan when using it is to hold the sponge from the positive pole stationary, near to the origin of the muscles, and to stroke or paint as it were the entire muscular surface with the sponge from the negative pole, gliding it in lines from the position of the positive. In using the constant Voltaic current both sponges must be held quite immovable, and so applied it differs altogether in its effects from the very same strength of current interrupted by moving the conductors. I will demonstrate these different applications upon the extensors of my left wrist and fingers—Faradism—Voltaism—Constant Current.
Fig. 14. Metallic Disk, covered with Wash-leather.
Fig. 15. Method of holding Sponge-holders with Sponges inserted.
Indirect, or extra-muscular electrization, next claims our attention. You will recollect that it is produced by acting upon the special nerve trunk and its branches, instead of by placing the rheophores upon the muscle itself. We may thus call a motor nerve into action without affecting the cutaneous nerves, and with a minimum of power of current, and necessarily a minimum of sensation which hardly ever need amount to actual pain. This method is preferable, therefore, in cases where we desire to produce muscular contraction and as little sensation as may be, and again when the sedative influence of the constant Voltaic current is required to be localized in any special nerve. In its application it is convenient to place a good-sized sponge connected with one pole upon an indifferent part of the body, such as the sternum, and to apply a pointed conductor from the second pole directly over the course of the nerve it is desired to act upon. Speaking generally, these motor points as they are called may be selected by reference to a good anatomical plate, but only approximately, for we know that it is common to find variations in the course of the nerves and in the mode of their distribution among the muscles, and this being so, it is well when we propose to act upon a motor or mixed nerve (which is not paralyzed), to make sure that we are localizing the current in it by producing for a moment the contraction of its muscles and then marking the spot by touching it with a pencil of nitrate of silver. This, of course, is only necessary where in our subsequent electrization we do not wish muscular contraction, as in the treatment of neuralgia.[12] I will demonstrate indirect electrization by Faradizing the median nerve in my left forearm above the wrist, and before it passes beneath the annular ligament of the carpus. It lies a little below the surface, between the tendons of the flexor carpi radialis and palmaris longus. You observe that its muscles powerfully contract and oppose the thumb to the other fingers, at the same time abducting it. There occurs also a slight flexure of the first phalanges of the index and middle fingers. Professor Ziemssen in his work on Medical Electricity has published some extremely accurate plates of the motor points of the body, and I have grouped together the more important of them in a chart or map for convenient reference.[13] Ziemssen’s method of procedure was to find out experimentally the points where the application of electricity most readily produced muscular contraction. He then marked these points with coloured chalk, and after a sufficient number of trials with nitrate of silver. Photographs of the parts thus marked were taken and afterwards transferred to the wood blocks. These figures may therefore claim to be true to Nature, although they may not be absolutely correct for every individual. Ziemssen verified their approximate exactitude by following the course of the nerves very accurately in the dissecting-room and observing their points of entrance into, and their course within, their muscles, with constant reference to the surface of the body; but he was not completely satisfied until he had determined the motor points upon the skin immediately after death, and before the reaction to electricity had disappeared, and submitted these points to the scalpel. The results of the three methods coincided perfectly.
We will next consider cutaneous electrization. I have already shown you that when the skin and the conductors are both quite dry, a Faradaic current of moderate power (and practically this form of electricity is always employed in cutaneous electrization) does not penetrate the skin, but is localized upon its surface. There are three methods of applying cutaneous Faradization—the method that we employed—that of “Metallic Conductors;” the “Electric Hand,” as it is called, in which the operator having applied one conductor to some little sensitive part of the patient’s body, holds the second in his left, and passes the back of his right hand over the points he wishes to excite, these points of the patient’s skin and the back of his hand being dry, and sprinkled with absorbent powder; and the “Wire Brush,” a brush of metallic wire, which replaces one of the conductors, and which is moved over the skin. With a strong Faradaic current this wire brush becomes the most powerful of all the excitants of the skin which do not disorganize its structure; in fact it was proposed by some scientific parliamentary philanthropist as a substitute for flogging in the navy, and I have no doubt that more intense pain may be produced by it than by any application of the cat, however well laid on!
The methods of electrizing internal organs need not detain us long. The rectum and muscles of the anus may be electrized by introducing into the rectum the rectal rheophore, a metallic stem insulated by gum elastic, and moving it over the internal surface, bringing it also into contact with the levator and sphincter ani. A well-moistened sponge connected with the other pole may be applied to the abdominal muscles or to the neighbourhood of the anus. The rectum must be first freed from fæcal matter.
The bladder is most readily electrized by the introduction into the rectum of the rectal rheophore, and into the bladder—previously emptied—of a curved metallic sound insulated by an elastic catheter to within an inch of its vesical extremity. This sound must be brought into contact successively with all points of the neck of the bladder. The uterus by the introduction of the rectal rheophore, connected with one pole, to the os uteri, and by the application of two sponges from the other pole, one to the abdominal parietes, the other to the lumbar region. The larynx, externally by one sponge to the nape of the neck, and the second to the exterior of the larynx; or, internally, a sponge to the neck as before, and the introduction by the aid of the laryngoscope of a small bit of sponge at the end of a curved metallic stem, insulated by a gum-elastic catheter, the current not being allowed to pass until it is seen by the laryngeal mirror that the sponge is in the desired position. The male genital organs by moist rheophores to the scrotum over the testicle; but if it be desired to excite the vesiculæ seminales, the bowel is first emptied, the rectal rheophore is then introduced and so directed that its olive-shaped termination may be brought into relation with the vesiculæ. For this purpose it is sufficient to move the rheophore from right to left and vice versá. A powerful current will penetrate the intestine and reach the vesiculæ, exciting them energetically. The circuit is completed by a second rheophore placed on an unsensitive part of the body.
In electrization of the central organs of the nervous system, the Voltaic current is alone used, and in its application to the brain, the sympathetic nerves, or the organs of the senses, especial circumspection must be employed. As a general rule it should not be had recourse to when central excitement is contra-indicated, and in all cases the minimum dose should be commenced with, and the application discontinued upon the occurrence of giddiness, nausea, or cerebral symptoms. With these precautions the brain may be electrized by well-moistened sponges applied to each mastoid process, to each temple, or to the frontal and occipital protuberances. The sponges must be held immovable. To galvanize the superior cervical ganglion of the sympathetic, one electrode of small size must be deeply pressed into the auriculo-maxillary fossa, and the other with a good-sized sponge applied over the sixth or seventh cervical vertebra, or to the manubrium sterni, close to the border of the sterno-mastoid. The spinal cord may be electrized by keeping one sponge, usually the positive, stationary, and moving the other up and down by the sides of the vertebræ, or one pole may be applied to the spine, and the other held to a nerve or muscle. The retina by a moistened conductor to the closed eye, and the second to the temple or to the mastoid process of the same side. The auditory nerve by one conductor tipped with sponge and inserted to the bottom of the meatus, the second being held in the hand of the opposite side; or the meatus may be filled with tepid water, and a metallic wire traversing the axis of a vulcanite tube may be immersed in the water, the second conductor being a well-moistened sponge to the nape of the neck. Direct application to the ocular muscles or to the conjunctiva is usually inadmissible, but one pole may be placed over the facial nerve below the ear, and the other applied to the closed eyelid, or the operator may use the forefinger of his right hand, covered by a finger-stall of wet linen as an electrode, passing the current through his own body by holding a moistened sponge from one pole in his left hand, the conductor from the second pole being similarly held in one of the hands of the patient. This application is not only convenient, but it is calculated to allay the fears of a sensitive patient: or a pointed conductor, covered with wet leather, may be connected with one pole, and its point held immovable and firmly pressed down upon the orbital margin, as near as possible to the position of the muscle it is desired to excite, while the patient touches at intervals the sponge from the second pole held by its insulating handle in the operator’s disengaged hand.
The chemical action of a continuous Voltaic current is sometimes useful in the removal or dispersal of tumours, and in the consolidation of aneurisms, one or more needles being introduced into the tumour, and connected with a Voltaic battery. I shall discuss this subject in our next Lecture, but I have here some of the most generally useful needles (Fig. 16), and I have had made for them holders with eyelet-holes for the attachment of conducting wires which render the operator independent of special conducting cords, for with a coil of insulated wire and a pocket knife he can fit up his needles in a few minutes in any way best adapted to his proposed operation.
Fig. 16. Electrolysis Needles and Needle-holders. By pressing the spring side B, the holder opens as shown in C, to grasp the needle D. The wire is twisted into the eyelet hole-A.
Having now considered the more generally useful methods of application, it may perhaps not be out of place to remind you in concluding this part of our subject that certain precautions are necessary to be observed. We must keep constantly before our attention that we are prescribing or administering an exceedingly powerful remedy, and with all new patients we should commence with a minimum dose, watch its effect, and if we need to increase it, do so gradually—e.g., muscular contraction being sought we must use the power just sufficient to produce it and no more—and so on with other applications; and it is especially necessary to use care in applying the Voltaic current to the face, neck, or any part of the head. Duchenne blinded a patient by suddenly applying a current from 40 cells to the facial muscles, and he had the candour to publish his misfortune. Sudden applications and sudden cessations should especially be guarded against. The cessation shock can, of course, only occur in cases where the conductors having been held immovable, and the current gradually increased, one or both of them has been abruptly, and it may be inadvertently, removed; and I have known a patient so frightened by such a cessation shock as to decline further treatment. The negative pole of a Voltaic battery will, if frequently applied to the same spot, soon cause a sore, and to avoid this the point of application should be slightly varied occasionally; and let me impress upon you, Gentlemen, the importance of always testing electricity upon yourselves before applying it to a patient. Use as many galvanometers, or so-called “instruments of precision,” as you like, but use in addition the back of your left hand as a convenient approximate test for the Voltaic, and your thumb muscles for the Faradaic current, except when about to apply electricity to your patient’s head or face, and make it then an invariable rule to first apply to your own face the same strength of current you are about to administer to your patient’s. If you authorize your patient to have treatment carried out at home impress this rule upon whosoever electrizes him. Under such circumstances it is especially imperative, for there is great belief, even with educated persons who ought to know better, that the benefit derived from electrization is in exact proportion to the pain given by it, and a little personal experience is a very wholesome corrective to such a notion. Graduate your dose, then, by the number of cells employed checked by testing its effect, and do this upon each application, for there is no certain means of securing that the strength of either a Voltaic or a Faradaic current shall not have varied from day to day.
We have now studied, Gentlemen, medical electricity, electrical instruments, and methods of application. In our next and concluding Lecture I propose to discuss the assistance that electricity affords us in diagnosis, prognosis, and treatment.