On the relation between muscular contractility and the nervous system / by John Reid.

  • John Reid
Date:
[1841]
Catalogue details

Licence: Public Domain Mark

Credit: On the relation between muscular contractility and the nervous system / by John Reid. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    This was continued for two months, and at the end of that time, the muscles of the exercised limb retained their original size and firmness, and contracted vigorously, while those of the quiescent limb had shrunk to at least one-half of their former bulk, and pre- sented a marked contrast wi^ those of the exercised limb. The muscles of the quiescent limb still retained their contractility, even at the end of two months; but there can be little doubt that, from the imperfect nutrition of the muscles, and the progressing changes in their physical structure, this would in no long time have disappeared, had circumstances permitted me to prolong the experiment.^ We believe, then, that we have adduced sufficient evidence to shew, that though the facts detailed by Miiller are perfectly cor- rect, yet the inferences which he has drawn from them, regarding the dependence of the property of muscular contractility upon the central organs of the nervous system, are untenable. Dr Marshall Hall has lately published some experiments bearing upon this question.^ He divided the spinal chord immediately below the brachial plexus, in six frogs, and then cut across the sciatic nerve in one of the posterior extremities of each animal. In these animals, then, both the volitional and excito-motory movements were paralysed in one extremity, while, in the other extremity, the excito-motory movements were retained, as the nervous communication between the muscles of that limb and the spinal chord was left uninjured. He found, after the lapse of a few weeks, that when galvanism was transmitted through the water in which the animals were kept, while the muscles of the limb which still retained their connection with the spinal chord were thrown into contraction, the muscles of the opposite limb remained quiescent. This difference in the degree of irri- tability in the muscular fibre of the two limbs, was observable when these were entirely separated from the rest of the animal. We have no intention of calling in question the facts contained in the memoir of this distinguished physiologist, nor the very inter- esting practical deductions which he has based upon them ; we only object to the correctness of his inference, that the source of muscular contractility is seated in the spinal chord. Before we can lay down a law in any of the sciences, or, in other words, ar- rive at a true generalization, it must include all the facts of 'the case; and consequently, if the facts which we have detailed in the above experiments be correct, the generalization at which Dr M. Hall has arrived, cannot be the true one, for it does not include these facts. To prevent this argument from being retorted upon ' Tlie application of the results of these experiments to the treatment of certain cases of paralysis, is so obvious as to rccjuire no illustration. 2 London Mudico-Chirurgical Transactions, vol. xxii.
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