metal handle to one end of the Tesla. Have the last person in line hold a spray electrode in his unoccupied hand so that the spray, six inches in length, strikes the other hand. We will observe rhythmic, muscular contractions in the hands of all the persons forming the chain, whether this chain be two or twelve persons. This shows the great pressure of the current.

If we take a fluoroscope and hold the spray electrode against its bottom, we will see the screen fluoresce, showing the actinic properties of this spray and spark.

The methods in which we can use the Oudin spray are two: one, the mono-polar method; the other, the bi-polar. The first

3

I-1. Connection from terminals of static to Leyden jars; 2. Connection from Tesla post to solenoid; 3. Connection from solenoid to small metal plate in contact with patient; 4. Connection from Tesla post to ground; 5. Connection from ground to large metal plate; 6. Felt between large metal plate and patient.

is practiced by having the patient on the insulated platform, or on the ground, while the operator holds the spray electrode far enough away to prevent the passage of sparks.

The second method is effected by having the patient on the auto-condensation chair, grounding the metal plate as well as one end of the Tesla, and holding the spray electrode at a sufficient distance from the part to be treated. The difference in the two methods is simply a difference in degree of intensity.

The same procedure can be adopted when using the spark. The spray and spark are chiefly useful in skin diseases, eczema, psoriasis, sycosis, warts, small epitheliomas, and varicose ulcers, etc.

Another method of using the Oudin current is that of autocondensation, as follows: seat the patient in a static armchair on the insulated platform. Make metallic connection to the top of the Oudin resonator by placing a large metal sheet (about 5 x 20

1-1. Connection from terminals of static to Leyden jars; 2. Connection from solenoid to vacuum electrode; 3. Connection from Tesla post to ground; 4. Connection from ground to small metal plate in contact with patient.

inches), against the bare skin of the patient's back, and connecting this by wire to the Oudin resonator. A patient thus connected is charged and discharged with every pulsation of this pulsatory discharge.

If we approach our clenched fist to within three to six inches of a patient thus connected, we will see a spray discharge emanating from the patient to our fist, or we may draw sparks from the patient's body with our knuckles.

This method has succeeded in aborting an attack of whooping-cough in three cases, the immediate effect being profuse perspiration, removal of fever, and production of sleep, followed by lessening of cough and vomiting.

The next step is that where we make a conductor of the body for the direct passage of the current. This is accomplished as follows: Have the patient seated in a small plain chair on the insulated platform. Fasten a metal plate to his back, or opposite any part we wish to treat, ground this plate and the Tesla, and attach the glass vacuum electrode to the top of the Oudin resonator after having first placed this electrode to the seat of disease.

This method has been successfully employed in pulmonary tuberculosis in ten cases.

We can also use the latter method for cataphoresis by either painting the medicament on the part or using a special electrode for the purpose.

It would seem that much of the therapeutic value of highfrequency currents is due to the actinic property of its spark and spray discharge, and in its power to produce chemical changes in the tissues, as is evidenced by the very great increase of the solid constituents of the urine, by the increase of the excretion CO,, as well as the positive increase in heat production and increased activity of the sweat glands.

High-frequency currents probably owe their remedial effects, in infectious diseases, largely to their power to check toxins, improve nutrition, and (when used in not too great amperage) to strengthen the natural defenses of the body.

148 West Seventieth Street, New York.

Discussion.

Dr. Edward C. Titus, New York City: The close attention to the detail work presented to us by Dr. De Kraft is worthy of great commendation. The results in the class of cases which he has shown us we get with no other modalities. His treatment of joint cases is certainly a revelation to me. For a long time I have treated cases of synovitis with the static wave-current followed by sparks which has given me good results. According to Dr. De Kraft's method we are able to obtain these results in a shorter period of time, and his claims are certainly worthy of our investigation. I think if we understand and properly apply these different modalities we shall find their therapeutic value to exceed that of medicinal remedies. I congratulate Dr. De Kraft upon the type of his paper.

Dr. Barshinger: I have made some experiments that seem to prove exclusively to my mind that the high-frequency current does penetrate the tissues. This may be demonstrated by apply

ing the electrode to the patient's chest; having him open his mouth, when you can draw a spark from the tongue. This would seem to show that there must be a penetration of the tissues.

Dr. William Benham Snow: While I feel that the electricity does penetrate under the conditions named, I would like to disabuse Dr. Barshinger's mind, for this is not proven by the production of the spark referred to; for, when a body is brought near enough for a spark to pass from an external source, it will be by conduction from an external capacity and no evidence that under other conditions the body is charged or that the current penetrates.

Dr. Edward C. Titus, New York City: I might call attention to the particular source of energy that Dr. DeKraft has described. We hear so much about high-frequency currents, but I think the term has become a misnomer, for it is not the high-frequency current, as it is commonly stated, that produces the penetrating effects, but the low frequency. I believe it was thoroughly stated at the last meeting of this Association that it was the currents of low frequency and high potential which possessed the greater penetrating qualities, that when we increased the frequency of the currents from different sources of energy above a certain standard, they did not penetrate the surface of the body, but passed over the skin.

The current generated from the coil has a local action. With the current from the static machine we get penetration and contraction. One action is chemical and the other is physical. From the coil we get local chemical action; from the static machine we get deep-seated physical contraction.

Dr. Donaldson: I thank Dr. De Kraft for enlightening my ignorance in this matter. I began the use of the Tesla coil in connection with my static machine with skepticism. I could not find any type of construction that was suited to the different apparatus in use, and I confess that I began using it without any expectation of real service. A very few cases have taught me that there is a real benefit from it, more particularly in those types of cases of mild pleuritic adhesions with slight temperature and some cough. These cases were very speedily relieved after I had attempted to relieve them by medical means and had failed. I did not understand that the author carried out his experiments with the Tesla coil, but with the Oudin

resonator.

Dr. De Kraft (closes): I use the first method employed in the use of the high-frequency currents from the coil. I use it only with the D'Arsonval current.

The question of penetration is largely a matter of method. If we use simply the spark and spray of the Oudin current our effect is largely surface. In that method whereby we

make the body a conductor of the Oudin current, where we ground the metal plate opposite the point we treat, it can be shown that the current passes in a direct line from the electrode to the metal plate. If the connection is proper under these conditions, you cannot draw any spark from any part of the body within an inch of the electrode. Close to the electrode you can draw a little current off, but the farther off, the less current you can get until two or three inches from the electrode you cannot draw off anything. If we take the chain attached to the metal plate and lift it off from the point where it is grounded, so that a spark of an inch or two will pass, we can get muscular contractions throughout the body. Especially is this so if that metal plate is over the back.