on the sixth cervical vertebra of the corresponding side, or on a spot lying below this, which is often with difficulty found, and sometimes is as low down as the loins. Remak adds that sometimes the proper points of irritation lie on the same side with the diseased extremities, and affirms that diplegic contractions can never be produced by means of the induction current.'

Fieber has confirmed the assertion that the ganglion cerv. sup. plays the chief part in exciting the diplegic contractions, and that the current must have the direction affirmed by Remak, also that the position given by him to the positive pole, and to the negative, below the fifth cervical vertebra, is necessary for the production of the contractions -on the other hand, he was able, contrary to the belief of Remak, to excite these contractions also by using the induction current. Moreover, Fieber observed similar contractions, as had Remak in the beginning of arthritis nodosa, in rheumatic paralysis of the arm, in lead paralysis, and in apoplectic paralysis: Drissen observed these, not only in the two noticed cases of vaso-motor paralysis of the extremities, but also in paralysis of the nerves of the arms following, probably, inflammatory irritation of the nerves; I myself saw them, among other instances, in a very animated young girl, having paralysis and atrophy of the upper extremities, consequent on chronic arsenic-poisoning, and they were induced as well by the use of the constant as by the interrupted current. Dr. Drissen and Dr. A. Eulenburg had an opportunity in this case to observe, with me, how the diplegic contractions were produced by irritating different points at a distance from one another: these set in, first, on placing the conductors on the customary places; secondly, on their application to the right or left side of the dorsal column, especially at the height of from the fourth to the

1 See Remak: application du courant constant, etc., pp. 27 bis 31. Die diplegischen Contractionen nach Versuchen an Menschen und Thieren erlautert. Berlin Klin. Wochenschrift, 1866, Bd. iii., No. 23, 25, 26.

eighth thoracic vertebra; thirdly, by placing one conductor on the pit of the stomach and the other on the above region of the dorsal column, and during this last application the contractions reached their greatest intensity, while they were much less pronounced when the poles were on the customary parts moreover, in this case the fixation of the ganglion cerv. sup. was not sufficient to produce the phenomena.

2. The centripetal reflex movements Remak' and Braun' have observed in old cases of apoplexy, and used therapeutically with success. These were caused, in Remak's case of thirty-eight years' standing, by strong contractions of the arm and leg muscles, as soon as a constant current was conducted through the nerves of the paralyzed arm or leg, and the contraction of the limbs was relaxed. In Braun's case the contraction of the fingers was loosened and the arm was lifted upward and backward by an ascending current through the N. peronæus of the paralyzed side-a phenomenon which did not appear under similar conditions on the healthy side. On the other hand, in the last case a centripetal action could not be produced through the N. medianus on the leg of the corresponding side.

To bring about galvanic irritation of the nerves of special sense, we seek to give the electrodes such a position that the intensity of the current shall have its maximum in the respective organ. In order, for instance, to act on the retina and the N. opticus, we place one conductor on the inner angle of the eye, and the other on the temple, avoiding, however, too strong a current, since in sensitive eyes the light produced by the galvanic action may excite retinitis. To affect the sense of taste, we place one conductor on the tongue and the other on the neck, etc.

For peripheric irritation by means of the constant cur

1 S. Galvanotherapie, p. 221.

Berlin Klin. Wochenschrift, 1865, Bd. ii., p. 123.

rent, with which Benedikt in Vienna especially has occupied himself,' we may use either the so-called spinal-marrow rootcurrent, by placing one, generally the copper pole, on the vertebral column, and stroking the latter with the zinc pole; or the spinal-marrow plexus or spinal-marrow nerve-current, by placing one pole on the plexus of the nerve and the other on its origin at the vertebral column; or the plexus nervecurrent, where one pole rests on a plexus and the other on one of its nerves; or the nerve muscle-current, where one pole rests on the nerve and the other on the muscle supplied by it. We may also, when a considerable portion of a nerve is accessible, place both poles on the same nerve, or finally one conductor on the muscle and the other on its motor point, and in regard to this last method we would refer to page 146, et seq. Naturally we may in all these operations allow the current to work either in an ascending or descending direction, and it may be stable or mobile.

18. u. A. Allgem. Wiener Med. Zeitung, 1863.

SEVENTH SECTION.

ELECTRICITY IN ITS APPLICATION TO ANATOMY, PHYSIOLOGY,

AND PATHOLOGY.

WE have already shown how, through local faradization by means of a frequently-interrupted current, not only each individual muscle, but also each muscle-fasciculus, may be brought into immediate contraction. Duchenne used these methods to ascertain in an exact manner the mode of working of each muscle, and he thereby disproved many errors found in the anatomical text-books, and showed that most movements were caused by a single muscle and not by the simultaneous action of different muscles. Bérard has consequently remarked that Duchenne, through the local application of the electric current, has become the creator of an "anatomie vivante."

In the following pages we will give a short résumé of his interesting investigations, referring for a closer study to Duchenne's works or to Erdmann's.'

I. Of the face muscles we ascribe to both Mm. zygomatici the office of drawing the corner of the mouth outward and upward; Duchenne observed that the M. zygomaticus major, in consequence of its attachment to the angle of the mouth, is active in laughing and in the expressions of merriment; and the M. zygomaticus minor, lying more within and forward, in crying and in expressions of sadness. The electrized M. pyramidalis expresses anger and threatening, the

1 iv. Aufl. pp. 94-164.

M. transversalis nasi derision and contempt; and the irritated M. triangularis nasi gives to the countenance the expression of lasciviousness. The M. subcutaneus colli is strained in wrath and terror, as well as in the expression of resignation. The M. frontalis draws the skin of the forehead, eyelids, and eyebrows upward-slightly contracted, it brightens the countenance more strongly, it expresses doubt, and when most contracted it indicates, with the simultaneous action of other muscles, agreeable surprise or dread. The M. buccinator draws the commissure of the lips strongly outward and forms long furrows on the cheek, which give the appearance of age, while the united action of the M. buccinator and M. zygomaticus major in some persons produces the lovely dimples on the cheek. The muscles of the tragus and antitragus contract the outward part of the ear, and have the office of protecting the ear from too powerful impressions, and sharp tones, while the muscles of the helix appear to be used for expanding this organ.

II. In regard to the muscles of the hand and arm, Duchenne showed that, when in the flexed condition of the hand and fingers we electrize the extensors of the fingers, at first the last two phalanges, then the first phalanges stretch out, and at last extension of the carpus upon the forearm takes place. The last two phalanges remain extended till the metacarpus forms an angle with the forearm, then they become flexed, while the first phalanges extend themselves still more. At the same time, the extensors spread the phalanges apart, which in the flexed condition were near one another. By irritating the extensor indicis proprius, the index-finger approaches the middle-finger; by irritating the extensor digiti minimi proprius, the little finger separates from the fourth considerably more than when contraction of the fasciculi, going to it from the extensor digitorum comm., takes place. It follows from this, that the extensor digitorum comm. and the extensores proprii not only extend the first phalanges, but also separate the fingers from