An experimental inquiry into the functions of the ophthalmic ganglion / by C. Radclyffe Hall.

  • Hall, Charles Radclyffe, 1820-1879.
Date:
[1846]
Catalogue details

Licence: Public Domain Mark

Credit: An experimental inquiry into the functions of the ophthalmic ganglion / by C. Radclyffe Hall. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    33/148
    was the same. Guarini’s experiment with strychnine is also in- validated by Dr J. Reid’s observation, that on poisoning a dog with Prussic acid, both pupils became equally dilated, notwith- standing one had been previously contracted in consequence of the removal of a portion of the vagus and sympathetic. The in- fluence of the sympathetic over the eye is not restricted to the iris. In the dog, experimental interference with the superior cervical ganglion, whether by section, compression, or complete removal, produces the same phenomena. Contraction of the pupil, retrac- tion and inversion of the eyeball, partial closure of the eyelids, protrusion of the cartilaginous membrane, and increased vascula- rity of the conjunctiva, with more or less intolerance of light, re- sult. (Dr J. Reid.) Of these effects, the retraction of the eye- ball and the protrusion of the third eyelid, are due to excitement of the sixth nerve ; the approximation of the eyelids, either to the same from retraction of the eyeball removing the usual support of the eye from the lids, or otherwise to excitement of the facial nerve causing contraction of the orbicularis palpebrarum ; the in- version of the eye, to excitement of the third nerve acting upon the rectus internus. To ascribe the contraction of the pupil, there- fore, to abolition of the function of the supposed dilating nerve, is to assume that the same injury of the superior cervical ganglion, which indirectly excites the function of several muscular nerves destroys the power of one, viz. the nerve for dilating the pupil. In that case the power of dilating the pupil would be permanently lost, which is not the fact. If, on the other hand, we suppose it to be stimulated in common with the rest, the nerve assumed to be sent to the iris through the superior cervical ganglion must be one for contracting the pupil, the addition of which to the third nerve seems unnecessary. A poisonous dose of prussic acid di- lates the pupils in all animals in which I have tried it. It can scarcely be supposed to stimulate the dilating, and at the same time to paralyze the contracting nerve. Destruction of the spinal chord produces maximum dilatation of the pupils (§ 38), which lasts for a considerable time. Assuming the existence of a spinal nerve for dilating the pupil, the destruction of the chord would cause the now unnopposed contracting nerve to lessen the pupil. And were dilatation of the pupil under the direct control of the chord through the medium of a spinal nerve, either enlargement of pupils should attend every instance of undue excitemenrof the spinal centre, which experience contradicts; or else the contract- ing force must greatly exceed the dilating, which is irreconcilable with the action of belladonna. We should also expect, as “ the spinal chord never sleeps,” that the state of the pupil during sleep ' rek'';riblc to nervous influence at all, would be that over which Uie spinal chord presideddilatation, according to the view in