Addressing you who are engaged in active practice, with little time to devote to medical electricity, it will, I think, be more acceptable for me not to weary you with a tedious discourse upon the elementary principles of electricity, for the practical application of these matters concerns rather the instrument-maker than the medical practitioner, and I shall discuss none of them, except incidentally, and with precise reference to their application to medicine. Besides, we know little of them, and I cannot forget that Faraday said that “he once thought he knew something about electricity, but the more he investigated it the less he found he understood it.” Let us then be content with its definition as a “Force,” “pervading all nature, latent in every substance, and liable at any moment to be excited by mechanical or chemical means.”
Nor do I propose to make these Lectures in any sense exhaustive, but, on the contrary, to include in them only such information as is essential, and such as you may readily, and without effort, retain in your memory. I shall direct especial attention to practical points which are of importance to the successful use of electricity; for from non-observance of small details of application many failures have resulted, the treatment getting a measure of discredit, which in strict justice should have attached only to the operator.
In the present Lecture I shall consider instruments, their construction and management, a dry subject, but an essential one, the first requisite of a good workman being complete familiarity with his tools, lacking which he will be the victim of constantly recurring annoyances and difficulties; for although the present position of electro-therapeutics is largely due to improved methods of administration, these methods would be impossible with faulty instruments, while, on the other hand, the most perfect instruments require a certain amount of skill and care in their management, and some acquaintance with at least the mechanical details of their construction; and without this rudimentary knowledge it is also impossible to usefully compare one instrument with another.[4]
My second Lecture will be devoted to the different methods of applying electricity, and my third and last to its uses in the diagnosis and treatment of disease.
Varieties of Electricity.
We make use of three varieties of electricity in medicine.
Firstly, of static or friction electricity, the electricity of glass and amber, appropriately called from its early investigator, Franklinism.
Secondly, of the electricity of chemical action, Galvanism, or better, Voltaism, the “Constant Current.”