Experimental rescearches on the post-mortem contractility of the muscles, with observations on the reflex theory / by Bennet Dowler.

  • Dowler, Bennet, 1797-1879.
Date:
1846
Catalogue details

Licence: Public Domain Mark

Credit: Experimental rescearches on the post-mortem contractility of the muscles, with observations on the reflex theory / by Bennet Dowler. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    rents act upon the muscles in the same manner as the nervous influence, and which it plausibly explains.”—(Anat. and Phys.) Indeed, Dr. W. Philip says these fluids are identical, while M. Matteucci, in his late prize essay on this subject, wholly denies the existence of these electric fluids or currents in the nerves, and maintains that all electrical actions in the body, are not the causes but effects of vital changes. According to M. De Manneville {^Precis, etc.), and Dr. Searle {London Lancet), life is but the sum of electricity. Dr. S. Dickson, of London, asserts, that “ Life is electricity in its highest sense, it produces all the changes in the living body, the brain and nervous system being the electric apparatus; the nerves, the moving powers. A remedy is a repulsive or attractive force, and acts by an electric vital affinity solely.” But, according to him, Medicina non agit in cadaver.^^ “ Bark is a motive power.” It might be urged that the motive power in post-mortem contractility is quicker than bark, and slower than electricity. Haller was aware of the influence of the spinal cord of certain animals over tlie muscles, when under galvanic excitation, or when pricked with a sharp knife, though he does not refer to the posterior roots.—{Phys., cccciii.) I know not that the spinal marrow in the human subject has ever been tested in the living state, by pricking or scratching ; and, as to exciting contractions in this manner in the dead body, credat JudcBus I In the examination of the spinal cord of many subjects, only a few minutes after death, not a case of contraction was seen, though, in the ordinary method of cutting, chiselling, and sawing on each side of the spinous processes of the vertebrae, all the roots of the spinal nerves, as they escape from the bony canal, must be irritated in every possible way by pricking, scratching, bruising, pinching and dividing. Plaller, and, I believe, all the electricians who have since his day experimented on this matter, constantly speak of convulsions being produced in the muscles. Now, a quivering, oscillating, agitated, irregular, or convulsed motion, is very different from regular intermitting extensions, pronations, supinations, which, in truth, simulate voluntary movements ; of which we will say more hereafter. The “ Medico-Chirurgical Review” gives the following account of the recent experiments of MM. Longet and Matteucci, who describe the effects of electricity on the posterior or sensitive roots of the spinal cord :— “ When these were separated from the cord, no contractions were excited by the electrical current, whatever its direction. But when they were still adherent to the medulla, they always gave rise to convulsive shocks on closure of the cir- cuit, whether the current was inverse or direct. It was evident, however, that these convulsions were owing entirely to a reflex action on the anterior roots; for, when the latter were cut across, all contractions instantly ceased. An inte- resting point, which their researches have elucidated, is the function of the anterior columns of the spinal cord, which are shown to possess an exclusively motor function.” I find, on referring to the transactions of the Academy, that M. Mat- teucci’s paper on “ Galvanic muscular currents” {sur les courans gal- vaniques musculaires), is founded on observations upon frogs continued from day to day for five months. These frogs were all taken from the same pond ; some were killed to ascertain the contractile function—{pour