Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.
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where the motory nerves have their entrance place into the muscle. It is from such a point,—besides these general and specific rules, a point or points on the surface of the body and limbs, whose lati- tude and longitude must be familiarized by experience in prac- tice, and, still better, by systematic pre-trials on the recent sub- ject, and on healthy persons, — that we can govern the action of the muscles most surely, most completely; and besides that, and which is of far more importance, to my mind, disturb and break up the abnormal polarity of the nerves most profoundly ; thus leaving them in a condition so that their natural equi- librium of function can be by nature's tendencies again estab- lished for permanency. If we desire to embrace in the current all, or as nearly all the larger branches of the nerve as possible, we must place one elec- trode over the highest reachable place for the entrance nerve, and the other over the forks of the first large radiating branches, as they enter and spread in the muscle, which will usually require the placing of the second electrode not far from the first. What was said in regard to the electrizing of the muscle or- bicularis palpebrarum will apply in some degree to nearly all muscles whose motory nerves, at the time, possess the requi- site amount of excitability ; for if we place one electrode on one of the border points,—and by this I always mean the en- trance place of the largest nerve of that muscle, — the other electrode may even be a little beyond that muscle, and yet pro- duce some considerable effect; but this latter has no value in practice. It may perchance become serviceable where we intend to place two muscles in motion simultaneously from their com- mon border point by means of one and the same current. The practised medical electrician can readily trace the form and ex- tent of each of the muscles on the face, and also the course and extent of the branches of the portio dura even within the mus- cle ; and besides, there often can be defined the course of the branches of the tri-facial, which are sensitive twigs, by the response in a sharp, lively pain, to the track of the electrodes, wherever they lengthwise or obliquely cross, cover, or embrace the fibrils of any of these nerves.