Tic doloreux is indeed a horrible malady; but one which, when properly considered, becomes very instructive. It admirably illustrates the views of Abernethy; and how ready he was to concede all that examination of the views of others which modesty and common sense require, as well as how superior his own were, both in philosophical acumen and practical value; first examining the views of others, and finding them defective, he, with the true philosophical spirit which first discovers what is wrong—
"Primus gradus est sapientiæ falso intelligere,"
The nerves are the organs from which we receive all our impressions from without; and when their ordinary sensibility is thus morbidly augmented, we may be persuaded that there is _something_ very wrong within.
The tic doloreux is one of the examples showing how cautious and circumspect, and how modest withal, Abernethy was in advancing to his own comprehensive views of disease; and how entirely antithetical the method he pursued in arriving at them was to that which attempts to cut the knot of difficulty by gratuitous hypotheses.
When this disease first began to attract attention, it was suggested that it might be cured by the division of the nerve. The phenomena of the nervous system afforded abundant grounds for mistrusting the soundness of this view. The tendency, however, to confound the more salient symptom of a disease with its intrinsic nature, caused such phenomena to be overlooked or little considered; and the consequence was, that where the nerve was divided, the treatment was sometimes entirely confined to that proceeding.
In the end, the operation disappointed expectation; and that which careful reasoning might have predicted as probable, was left to be determined by experiment, In some cases, circumstances concurred to produce temporary relief; but on the whole the operation was a failure.
In the case he here published, Abernethy removed a little bit of nerve from a lady's finger. As she had suffered severely, and he was anxious to give her more permanent relief, he did not rest satisfied with merely dividing the nerve. For about nine months the lady was in comparative ease; but then the sensation returned. He remarks on the interest attached to this return of sensation, and observes on the analogy it suggests between the supply of blood, and that of nervous power. For if the vessels conveying the former be tied or obstructed, the supply is gradually restored through collateral channels. The return of the nervous functions, after the removal of a portion of the nerve, seemed to favour that view of the nervous system which regarded as the proximate cause of the phenomena some subtle principle or other, like electricity or magnetism, or some analogous power, of which the nerves might be the conductors.