ON THE FEELINGS ASCRIBED TO THE SENSE OF TOUCH,--AND ANALYSIS OF THESE FEELINGS. In my Last Lecture, Gentlemen, I finished the remarks which I had to offer, on our sense of _hearing_; and in the conclusion of it, had begun the consideration of a very important order of our feelings, those which belong to the sense of _touch_. Of these, I may mention, in the first place, the sensations of _heat_ and _cold_,--sensations that arise from affections of our nerves of touch, or at least from affections of nerves, which, as equally diffused and intermingled with them, it is impossible to distinguish from those which constitute our organ of touch, the same wide surface rendering us sensible, as it were, at every point of warmth as of pressure. I have also remarked to you, how little analogy there is of our sensations of warmth, to the other sensations commonly ascribed to this organ; and the great difference of the feelings, has led some physiologists to believe, that the organs of sensations so different, must themselves be different. But even though the sensations were as dissimilar as is supposed, there is no reason _a priori_ to believe,--and to experience, it is evident, that, in this case, we cannot appeal, so as to derive from it any ground for believing,--that sensations, which are very different, must arise from affections of different organs. As far, indeed, as we can safely appeal to experience, in this very case, there are sensations which we never hesitate in referring to our tactual nerves, as different from the more common sensations ascribed to touch, as the sensation of warmth itself. I allude to the pain of puncture or laceration of the skin. Indeed, if the brain be ultimately the great organ of all our sensations, it is evident that we must refer to affections of _one_ sensorial organ, not the various feelings of touch only, but, with them the still greater variety of feelings, that constitute our sensations of smell, taste, sound, and colour. But are we indeed sure, that there truly is that great dissimilarity supposed, or may not our belief of it arise from our reference to touch of sensations that truly do not belong to it? Such, at least, is the opinion, to which, I think, a nicer analysis will lead us. The primary original feelings, which we owe to our mere organ of touch, I consider as of a kind, all of which are far more analogous to the sensations of warmth, or of pain on puncture, than to the perceptions of form and hardness, which are generally regarded as tangible. Before entering on the analysis, however, it will be necessary to consider, what are the sensations which we are supposed to owe to this organ.