Page:Philosophical Review Volume 1.djvu/645

No. 6.] sensation X in a painful phase. When one presses a needle into the skin, the touch sensation may precede the pricking pain; but this may result from the fact that certain other nerve elements than those of touch are affected after the needle has pierced the skin, namely, those which bring about the pricking sensation. I am perfectly willing to believe, indeed, that a set of nerves and nerve terminals other than those affected by action upon the surface organs of pressure, heat, and cold, may be discovered, and that we shall find them to be brought into action by rupture of the surface, by laceration, by cutting, by piercing; and I think it will be allowed as possible that the action of these nerves under the conditions involved in the usual experiment must always be painful; but there is here surely no crucial argument to show that specific pain nerves have been discovered. In those morbid cases where several seconds elapse after the sensations of touch and cold are felt before the pricking pain arises, we may surmise that some disturbance has occurred which has delayed the action of the nerves affected by the laceration or cutting or pricking of painful degree. Such restrictions of activities we find in the other recognized sensations. The facts of analgesia which have been held to tell in favor of the existence of special pain nerves may also be found to be explicable in some similar manner. We may interpret the observed results to mean that the capacity to experience one form of sensation (e.g. cutting, pricking) in a certain part of the body may be cut off, together with the capacity for pain-giving which goes with it, without cutting off in the same parts the capacity to experience other sensations (e.g. those of pressure, heat, cold) with their capacity for pain-giving.

5. Schiff and his followers have been led to argue for special pain paths in the spinal cord, by the observation that under certain morbid pathological conditions or by the use of anæsthetics all the generally recognized senses may be lost to the lower extremities, whilst the pains produced by pricking or cutting remain. But, as in the case preceding this, it certainly is possible to argue from these observations that the other sensations are cut off, leaving only the sensation of