Dr. Hooper's Physician's vademecum, or, A manual of the principles and practice of physic / [Robert Hooper].

  • Robert Hooper
Date:
1842
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Licence: Public Domain Mark

Credit: Dr. Hooper's Physician's vademecum, or, A manual of the principles and practice of physic / [Robert Hooper]. Source: Wellcome Collection.

    63/512 (page 51)
    govern the transmission of nervous influence, though it has left the nature of that influence involved in the same obscurity which hangs over the real essence of light, heat, or electricity. Ihe ettcct of the division of a nerve is familiar to every one. If the nerve be one of sensation, irritation of the branches or trunk of the nerve below the point of division causes no pain ; if it be a nerve of voluntary motion, neither the will nor a stimulus applied to the nerve above the point of division can cause the muscle to which it is distributed to contract. On the other hand if the voluntary nerve be irritated below the point of division or the sen- tient nerve above it, motion takes place in the one case, and sensa- tion m the other •, the sensation being referred to the parts sud- phed by the extremities of the nerve. This law of sensation is strikingly illustrated in cases of amputation of an arm or a le w..ere irritation of the divided extremity of the nerve is referred to le fingers or toes of the lost limb, and that even for years after its removal. A knowledge of the fact that irritation of the trunk hI.VT11.6111 Produces pain, not in the trunk itself, but in the parts to which its branches are distributed, is of constant appli- cation m the treatment of disease, and tends to destroy our confi- rCRCrhe dlT°n o/— aS a remcdy for pains in the parts fnln 1 t 'T SUpi, y- A great many cases oftic-doloreux have been found to depend upon some cause of irritation as a tumor or sni cula of bone existing at the origin of the nerve. 1 Although pressure applied to a sentient nerve causes min in h,, parts supplied by its branches, a still stronger pies^umTrolcet pam in the trunk of the nerve itself. Severe Leal injury to a nerve of sensation or voluntary motion destroys its power as -i con due tor of nervous influence, but it affects the nerve itself on IJ locall} , for nutation of the portion of the uninjured nerve wM l ^ in connexion with the brain, produces sensation,' and that of tlL ’'S t.on of nerve in connexion with themuscles tion. When, however, a nerve of motTon is^ co,ntrac- through its whole length, it loses its property of excitW n',° “i^’ contractions, and sometimesthe muscle itself - An* Scular cannot be made to contract by any stimulus lmwn m akihty,und Experiments on animals haveIm!gh? of the nerves, which may be advantaccouslv l 8 1 me J)roPertles pathologist. In the first place iitSC Lvdh “ Td by the that all stimulants applied to the nerves in the dead S & < 0uM’ nearly the same way, and produce effects diffm-; !°d/’ act ln Of such stimulants, the electric and „ 1 ™erely in degree, effectual, and they have been acJordinclv cLnl^1'^ -lre the most experiments on the properties oftM7 ®Dpl,°?ed m a]m°st all have shown, that the nerves, when imufaTo'., exPeri™nts act as mere conductors of the calvanL m^ b/ ga,IvanJsni- Jo not !haroughhthe muLlc! ^ 'ra™8e!y by any degreeof mechanicaHrrftiftio^a^Sedto^ane^eLfsemiation^ k 2