From the above observations, it will be plain that, when we wish to bring a diseased organ under the influence of the _positive_ pole, we must carefully place our electrodes so that none of the organ, or none of the diseased part of it, shall appear on the positive[B] side of the _central point of the circuit_; it being understood that the current moves as nearly in direct lines as the best conducting medium will admit. Or again, if it be desired to bring a diseased organ, or any extended part of it, under the influence of the _negative_ pole, we must first calculate in placing our electrodes about where the central point will come, and then so apply them that no part of the lesion or disease shall appear on the negative[B] side of the central point; otherwise so much of it as lies on that side will come under the force of the wrong pole, and thus be affected in a way the opposite of what was intended. The characteristic influence of each pole is felt throughout its own half of the circuit. DISTINCTIVE USE OF EACH POLE. I have said that every disease is preternaturally either positive or negative. I have further said, that the application of either pole to a given part produces an effect the opposite of what would be produced in the same part by a reversal of the poles. The way is now prepared for me to announce THE CENTRAL PRINCIPLE of our system of practice. The reader will bear in mind that all acutely inflammatory or hypersthenic affections are electrically _positive_ in excess--having too much vital action--being _overcharged_ with the electro-vital fluid; and that all paralytic diseases, or those of a sluggish, azoödynamic character, are electrically _negative_--having too little electro-vital fluid--too little vital action. It is a universal law of electricity that positives repel each other, and that negatives repel each other; but that positives and negatives attract each other. This is a principle of electric action everywhere known, where any thing is known on the subject. _We appropriate it practically to therapeutic purposes._ Therefore, when I wish to repress or repel inflammation, which is electrically positive in excess, I put the positive pole to it; or, at least, I bring it under that half of the circuit with which the positive pole is connected, and as near to the pole or electrode as possible. And because two positives repel each other, and also because the direction of the current is always from the positive to the negative pole, carrying the electro-vital fluid with it, either I must withdraw my positive electrode, or that excess of electro-vitality in the diseased part which makes it morbidly positive, and thus produces inflammation, must give way. I _will not_ withdraw my positive pole, and therefore the positive inflammation _must_ retreat and be dispersed. In treating this case, I will place my _negative_ electrode either on some healthy part, or, if there be perceptible anywhere in the system a morbidly negative