Experimental researches applied to physiology and pathology / By e. Brown-Séquard.

  • Brown-Séquard, Charles-Edouard, 1817-1894.
Date:
1853
Catalogue details

Licence: Public Domain Mark

Credit: Experimental researches applied to physiology and pathology / By e. Brown-Séquard. Source: Wellcome Collection.

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

    14/140 (page 2)
    a.—Source of the reflex faculty in the spinal cord. Notwithstanding the experiments of Redi, Whytt, Prochaska, Unzer, Senac, Fontana, Caldani, Sir G. Blane, Fray, Legallois and many other experimenters; and notwithstanding the much more important experiments of Marshall Hall, Miiller, Grain- ger, Volkmann, Kurschner, Pickford, de Martino, Buchner, Mayer, Paton and Stilling, the existence of the reflex faculty, after the spinal cord has been separated from the encephalon, is not considered by all physiologists as a proof of the independence of the spinal cord. J. W. Arnold and Flourens still maintain that the medulla oblongata is a centre, giving life to the other parts of the nervous system. The reflex faculty possessed by the spinal cord after it has been separated from the encephalon, is considered by J. W. Arnold as a remainder of something given to the spinal marrow by the encephalon, before their separation. My experiments prove the incorrectness of that opinion.* I have found that after having exhausted the reflex faculty by putting it in action, energetically and frequently, in an animal on whom the spinal cord is separated from the encephalon, it reappears, and becomes soon as energetic as before, provided that the cir- culation of blood takes place in the cord. Moreover I have found, that if the reflex faculty is put in action frequently, it is able to produce an immense quantity of action: thus, for instance, it can stimulate sufficiently the muscles of a frog's leg to make them raise, in an hour and in divided portions, about twelve pounds, to the height of about two lines. In a pigeon the reflex faculty is able to stimulate the muscles of a leg so far as to make them raise fifty pounds, by fractions, in an hour, to the height of more than one inch.f I shall add two other decisive proofs :—1. The reflex faculty is very weak in frogs immediately after the spinal cord has been separated from the medulla oblongata, and it increases after- wards, as R. Whytt and Marshall Hall have discovered. I have stated that it increases so much that the posterior limbs are able * See:—Recherches et experiences sur la physiologie de la moelle epi- meje. These inaugurale. Paris, 3 Janvier, 1846.—Comptes rendus des seances de l'Academie des Sciences. Paris, 1847 T. xxiv. p. 849. t See Gaz. Med. de Pari?. T. 4. 1849. p. 233.