from influence machines, may be calculated to afford 1,500,000 oscillations or alternations per second. Mr. Tesla employed 20,000 per second without Leyden jars, and the frequency with Lejden jars was calculated to equal from 1,000,000 to 1,500,000 per second.

Professor Thomson's alternating current was derived from an alternating dynamo machine, whose highest number of alternations was about 8,000 per second.

M. D'Arsonval's arrangement appears to admit of absolute accuracy in the rate per second up to 10,000 per second, since he employs a specially constructed alternating current dynamo, whose product is a sinusoidal or even wave current. He states, that by the aid of powerful Ruhmkorff coils, condensers, and induction coils, he carries the frequency of interruption up to 1,000,000 per second, while the current strength is live amperes. When we compare these figures with the 200 per second rate of the ordinary medical induction coil, it is plain that we are treading on different ground, and there is no doubt that in high frequency, high potential currents, that is to say in currents which are of high electromotive force, and which alternate or flow in opposite directions a great number of times per second, we possess in medicine an ally as valuable in the cure of disease as any other type or modality of current like the galvanic and the faradic or ordinary frequency of interruption.

To-day, then, we may obtain the currents under discussion:

1. From Morton's apparatus, viz., from the influence machine by condenser currents; (1881.)

2. From Tesla's apparatus; (February 21st, 1891.)

3. From Thomson's apparatus; (March, 1891.)

4. From D'Arsonval's high frequency sinusoidal apparatus; (February 24, 1891.)

But, since it is the Tesla experiments, performed with apparatus capable of affording an alternating electrostatic field of great energy, which have in reality brought into prominence not only the electrostatic phenomena of influence machines, but also all electrostatic phenomena of currents, I think it best to abandon the historical order in favor of one which has served, and continues to serve to demonstrate the subject most fully, and by effects utterly impossible to obtain in degree from any influence machine.

( Sept. 20,

Franklinism Or Electrostatics In Medicine.
(Statical Electricity.)

Before touching more fully upon any one of these three specialized forms of high potential, high frequency currents, we must study briefly that progenitor of all high potential, high frequency currents, the electrostatic or friction or influence machine, its product, its uses, and place in medicine.

Referring in a recent interview to the possibility, already proved by experiment, of the transmission of energy through the air. Mr. Tesla says: '"The plan I have suggested is to disturb by powerful machinery the electricity of the earth, thus setting it in vibration. Proper appliances will be constructed to take up the energy transmitted by these vibrations, transforming them into a suitable form of power, to be made available for the practical wants of life. Primarily, the agent that J propose to use consists ofan old fashioned electrical spark such as they derive from a Leyden jar. This is rapidly discharged back and forth a great number of times. Each time that the spark seems to pass, it is in reality passing hundreds of thousands of times, and each time it passes it sets up these waves in the ether, which extend out into space. In other words, the result of the experiment is to disturb the equilibrium of the ether."

Primarily also we may say, in a minor degree, in medical administrations of statical electricity, the agent which the physician uses_ is the spark; the electric ether vibrations are 6imilarily 6et up, and the appliance attuned to take up the energy transmitted by these vibrations is the human l>ody, with all its complexity of delicate physiological mechanisms, of delicate cell and fibre, themselves already vibrating with the function of life.

The spark then demands our first attention. [Assistant here turned the crank of a large Iloltz machine.]

A few brief revolutions of the wheels of this great Iloltz machine, and you see a torrent of sparks passing between the discharging rods. One of our number1 kindly allows himself to be mounted upon this insulated platform connected by a brass rod to the machine, and attest for us all the peculiar sensations of the electric charge, while again when I draw sparks from various parts of his body, you yourselves cau see the results of the muscles thrown into activity. A spark to the biceps raises a dumb-bell

1. Mr. W. J. Jenks, Member of the Institute.

grasped in his hand; another to the triceps throws the arms violently backward; his fingers extend and flex, as the corresponding muscles are touched; a spark to nerve trunks produces the familiar hand postures, just as when the ulnar or median nerves are excited in galvanism or faradism. Before your eyes are taking place profound excitations of nerve and muscle, visible, objective evidence of the power of this current which has been said by some doctors to be superfical, and not to penetrate beneath the skin. Were onr patient's temperature below the normal, as is more commonly the case than is suspected in many chronic diseases, you would find that it rose to normal. In fact, had we time to examine our patient more critically, we could determine with positiveness alterations in his pulse and temperature, and the amount of urea, and phosphates excreted. We could, in fact, establish great alterations for good in the chemical organic exchanges or oxygen combustions which are the essence of health, and equally the essence of cure Evidently we have before us a medical instrumentality of great power, even though it be the ancient Holtz machine whose phenomena have been too long neglected, both by the electrician and the physician.

Striking as are the differences between the electric product of the influence machine and our small galvanic and faradic exciters of electric energy, in reality the differences are more apparent than real, and the kinship of the different modalities of electricity, however excited are most easily established.

With the electric product of this machine we may repeat in lesser degree any experiment which may be accomplished by the galvanic or faradic currents.

That form of electricity, known as statical, has an enormous E. M. F. and low amperage; that known as galvanic, an enormous amperage and low E. M. F.; but neither is without one element or the other; it is merely a question of degree or ratio.

The so-called dynamic or current electricity, of the physician is also static, while the static is also dynamic or current electricity. While a Holtz machine exhibits a voltage of 100,000 to a spark one inch in length, or say, easily a total voltage of 1,000,000, represented by a spark ten inches in length, a voltaic cell exhibits a total voltage of only 1£. But the cell represents many amperes, while the machine represents merely a very small fraction of an ampere.

In medical work no deductions based upon these facts can be justly cited for the purpose of making invidious distinctions as to ( Sept. 20,

their respective curative value. Preponderating c. s. does its special work, and preponderating E. it. F. does its special work. It is merely a question of the work to be done. Knowing these differerences, the physician selects one or the other, together with some one or more of its special properties, and pits a given producible effect against a known or presumed condition of disease; this is a scientific method in contradistinction to simple empiricism.

Historical.—The spark and frictional electricity have long held sway in medicine, beginning with the time in 1730, when Stephen Gray discovered conduction and insulation, and drew sparks from a boy suspended by strands of horse-hair. It was the Abbe Nollet, however, who shortly after drew the first spark with the idea of curing disease; that spark marked the dawn of electro-therapeutics. Then followed the brilliant discoveries of the older philosophers and of the doctors—both of science and of medicine—who floundered about in their attempts to establish the identity of electricity with nerve force, with vital force, witli life itself, and thus hoped to find the elixir of life, and probe that deepest mystery. The miasm of their speculations yet clings to the purlieus of medicine. And yet to the mind unaccustomed to scientific thought, the modern view that electricity and light are identical, seems almost as marvellous.

In connection with early electro-therapeutics, it is interesting to us Americans to recall that Benjamin Franklin in 1752 in Philadelphia was treating paralytics by shocks from his Leyden jars. One patient, a young lady, who had for ten years been tortured with convulsions, thus quaintly describes her experience:

'* At length my spirits were quite broke and subdued with so "many year's affliction, and indeed I was almost grown desperate, "being left without hope of relief. About this time there was "great talk of the wonderful power of electricity; and as a "person reduc'd to the last axtremety is glad to catch at any "thing, I happened to think it might be useful to me. Altho' I "could have no encouragement from any experiment in the like "case, I resolv'd to try, let the e'ent be what it might; for death was more desirable than life, on the terms I enjoy'd it. Accord"ingly I went to Philadelphia, the beginning of September, 1752, "and apply'd to B. Franklin, who I thought understood it best "of any person here. I receiv'd four shocks morning and eve"ning; they were what they call 200 strokes of the wheel, which "fills an eight gallon bottle, and indeed they were very severe. "On receiving the first shock, I felt the fit very strong, but the "second effectually carry'd it off; and thus it was every time I "went through the operation; yet the symptoms gradually de"creased, 'till at length they entirely left me. I staid in town "but two weeks, and when I went home, B. Franklin wns so "good as to supply me with a globe and bottle, to electrify my"self every day for three months. The fits were soon carried off, "but the cramp continued somewhat longer, tho' it was scarcely "troublesome, and very seldom return'd. I now enjoy such a "state of health, as I wou'd have given all the world for, this

"time two years, if it had been in my power, and I have great "reason to hope it will continue."

I will merely remark further in passing, that the discovery of the Leyden jar in 1746, the discoveries of Galvani and Volta about 1800, and of induction electricity, completed by 1840, each formed historical epochs which gave to medicine respectively, franklinism, faradism and galvanism.

The Influence Machine And Its Adaptation To Medical Use.

It is here enough to say of an influence machine, that it, like any other device for exciting electricity, presents two polar terminals;