I next repeated my observations upon a more extensive scale, at the St. Mary-le-bone and St. Pancras Infirmaries. There were two exceptions to the rule ; whilst the numbers in which the phenomena as already described were observed were considerable.
These exceptional cases I shall notice parti cularly hereafter. I must now remark that these observations seem, even more than those of Prochaska, Nysten, and Legallois, at vari ance with the experiments of Professor Miller and Dr. Sticker. Before I proceed to discuss this question, I must, however, detail some ex periments of my own.
They were made on six frogs. I divided the spinal marrow immediately below the origin of the brachial plexus ; and I removed a portion of the ischiatic nerve of the right posterior ex tremity. I had immediately, or more remotely, the following interesting phenomena.
1st. The anterior extremities alone were moved spontaneously; both posterior extremi ties remaining entirely motionless, when the animal, placed on its back, made ineffectual efforts to turn on the abdomen.
2d. Although perfectly paralytic in regard to spontaneous motion, the left posterior extre mity, that still in connexion with the spinal marrow, moved very energetically when sti mulated by pinching the toes with the forceps.
3d. The right posterior extremity, or that of which the ischiatic nerve was divided, was en tirely paralytic, both in reference to sponta neous and excited motions.
4th. After the lapse of several weeks, whilst the muscular irritability of the left posterior ex tremity was gradually augmented, that of the right was gradually diminished, phenomena ob served when the animal was placed in water, through which a slight galvanic shock was passed accurately in the direction of the menial plane.
In this interesting experiment we have, then, first the phenomena of loss of spontaneous mo tion on removing the influence of the brain, the excited or reflex actions remaining ; and the loss of these on removing the influence of the spinal marrow; secondly, in the case of mere cerebral paralysis, we have augmented irritabi lity, and in that of the spinal marrow we have the gradual diminution of this property.
5th. Strychnine being now administered, the anterior extremities and the left posterior extre mity, or that still in connexion with the spinal marrow, became affected with tetanus ; but the right posterior extremity, or that severed from all nervous connexion with the spinal marrow, remained perfectly flaccid.
6th. Lastly, the difference in the degree of irritability in the muscular fibre of the two limbs was observed when these were entirely separated from the rest of the animal.
In a word, the muscles of the limb para lysed by its separation from both cerebrum and spinal marrow, had lost their irritability; whilst those of the limb separated from its connexion with the cerebrum only, but left in its con nexion with the spinal marrow, not only re tained their irritability, but probably possessed it in an augmented degree. The next question came to be,—Do these phenomena obtain in the human frame? I visited a patient affected with hemiplegia, including paralysis of the face, and I passed a slight galvanic shock through two pieces of metal, of which one was placed over each cheek. The muscles of the paralytic side were most affected. I repeated the expe riment with the same result. I now compared with these, two cases of injury of the facial nerve, passing the galvanic shock in the same manner, through the fibres of the orbicularis : it was now the muscle of the healthy side which was affected by the galvanism, the eyelid of that side being closed, whilst that of the para lytic side gaped as before. I next compared the effect of galvanism in two cases of complete paralysis of the arm, one heiniplegic, the other the result of dislocation of the shoulder. The muscles of the former were more, those of the latter less, irritable than those of the healthy arm respectively, as were also those of the arm of a patient affected with the paralysis induced by lead. Lastly, I compared the cases of pa ralysis of the lower extremities, one arising after pertussis, and therefore cerebral, the other, I think, from disease within the lumbar verte brae: in the former there was augmented, in the latter, diminished irritability.