The mechanical effect of the forward end of the current, or that part of it which is under the negative electrode, is to relax, expand and weaken; while that of the rear end, under the positive electrode, is to contract and strengthen. A moving ship disperses the waters at its bow, but draws them in at its stern. The bullet shot from a gun, in passing through a plank, leaves the perforation closed where it enters in, but wide open where it comes out. Thus, in physics, the advance end of a moving body tends to disperse the element through which it is passing, while the rear end tends to its contraction. Analogous to this are the mechanical effects of the different ends of an electrical current in the living tissue. When, therefore, we wish to relax a muscle that is unnaturally contracted, as by rheumatism or otherwise, we must bring it under the forward end—the outward current—the negative pole. If we desire to contract ligaments or muscles that are abnormally relaxed, (not atrophied), as in prolapsus uteri, we must subject them to the rear end of the current—the positive pole. Parts that are unnaturally contracted are electrically negative in excess, and need to be made more positive. And parts that are unhealthily relaxed are too positive, and should be made more negative. We make a part more positive by applying to it the negative pole, and more negative by applying to it the positive pole. Parts spasmodically contracted are acute and positive; those permanently contracted are chronic and negative.

RELAXED AND ATROPHIED CONDITIONS.

I alluded, above, to a distinction between a relaxed and an atrophied condition of an organ. There is such a distinction, which should be carefully observed while treating parts so affected. An atrophied muscle or organ becomes soft and flabby from lack of nourishment. But this condition is not properly one of relaxation. It is rather a diminution—a thinning out of atoms, by wasting without replenishment. Such a condition is always negative, and requires treatment under the negative pole. On the contrary, relaxed parts, such as appear in prolapsus uteri, and in the sagging down of the diaphragm, with the thoracic and abdominal viscera, exhibit no lack of nutrition or of vital action. Relaxation is a loosening of atoms from each other, more or less, without loss of aggregate weight; and implies a condition electrically positive in excess, and calls for treatment with the positive pole.

GENERAL DIRECTIONS OF THE CURRENT.

Negative affections, as a general rule, are best treated with the upward-running current—the positive pole being placed at a lower point than the negative. Inflammatory affections, and other plus conditions, for the most part, should be treated with the down-running current, keeping the negative pole at a lower point than the positive. But these rules admit of frequent exceptions, which every practitioner's experience will soon reveal.

The downward current, running with the downward and outward course of the nerves, tends to depletion and weakness, for the reason that it runs off from the system the electro-vital fluid. The upward current, on the other hand, running against the nerves, inward towards their source, feeds the system with fresh electricity, and gives a tonic effect. Yet for this purpose, it must not be too long continued, nor of too severe strength, lest it overtask and irritate the nerve-sheaths.

In treating a paralyzed organ, the current should commonly be run from a healthy part, whether that require it to be directed downwards or upwards. For example: In treating a paralyzed foot or leg, the positive pole should be upon the lower part of the spine—at the coccyx—or even under the sole of the opposite foot. It is best to alternate between these positions. So in treating a paralyzed hand or arm, let the current be run from the upper part of the spine, and frequently also from the opposite hand. With the negative electrode, treat all over the paralyzed parts. Yet it is well, in these cases, often to reverse the direction of the current for a brief period at the close of the sittings, say one to two minutes, for the purpose of rousing the nervous susceptibility, and to prevent exhaustion from too continuously running off the electro-vital fluid.

TREATING WITH ELECTROLYTIC CURRENTS.

For decomposing and carrying off unnatural growths, as fistula, ficus, glandular enlargements and other tumors, it is often best to dilute the electrolytic quality of the galvanic current A B with one or both of the Faradaic currents, as by taking A C or A D instead of A B. But malignant and poisonous affections, as scirrhus and other varieties of cancer, and also cases of infectious virus, demand continually, or with but occasional exceptions, the primary galvanic current A B. ☞In treating these malignant affections, the current should be run through as short a distance of healthy tissue as possible, yet so as fairly to reach the diseased part. And whether this part be brought, for a given time, under the one pole or the other, the opposite pole should be attached to the long cord, so as to throw the central point of the circuit, not in the person of the patient, but out on the long cord, thus bringing the entire organic parts though which the current is passed on one and the same side of the center, and so, under the ruling influence of the same pole.

Those diseases which require the chemical or electrolytic currents should, for the most part, be treated under the negative pole, particularly those which need the galvanic current A B, and also old ulcers and chronic irritation of mucus surfaces. Glandular enlargements not of scirrhous character, and excrescent growths not poisonous, may often be reduced, and perhaps sometimes cured, under the positive pole. But my own experience, even with these affections, is that it is better to treat them under the negative pole until they come to assume, as sometimes they will, an acute state, when the positive pole may be used with success. If, however, it appears desirable to produce a cauterizing effect, this must be done by persistent treatment under the negative pole of a strong A B or A C current, and, if the disease be external, with a small pointed electrode.