966 CUTANEOUS SENSATIONS. 



to state the problem adequately, to include with it some reference to 

 other pains than the cutaneous. The general trend of the evidence will 

 serve to indicate the direction in which the answer to the special case 

 under consideration will in all likelihood ultimately be found. 



Some authorities attach to the skin sensory impressions of " pure contact " l 

 and of "movement,"' 2 which they regard as different from tactual or thermal. 

 Such sensations, however, in so far as they differ from simple tactual 

 impressions, seem to do so rather because of the nature of complex 

 elaborations from tactual impressions. Hence they will not be dealt with here 

 as specific and distinct from touch. That common sensation arising in the 

 skin, of which the chief characteristic is pain, cannot be so dismissed. 



Eegarcling the physiological nature and mechanism of pain there 

 may be taken one of the three following views — (1) Pain may be 

 a feeling inherent in and appearing under certain circumstances in any, 

 each, and all of the separate senses. 3 (2) Or it may be a quality con- 

 ditionally arising in and limited to certain only of the species of sense. 4 

 (3) Or it may itself be a particular species or mode of sensation, the 

 product, and the only product, at least in certain varieties, of a specific 

 sense. 5 On the last-named view, it should be generated by the reaction 

 of a special neural mechanism, possessing specifically distinct peripheral 

 nerve-ends, and specifically distinct sensorial mechanisms in the 

 central nervous system. 



Common experience teaches that a spot of skin, under moderate press- 

 ure, gives merely touch, while under extreme pressure it feels pain. The 

 popular and the at first sight most natural, indeed almost intuitive, 

 view of the causation of cutaneous pain, is that which regards it as 

 resulting from excessive stimulation or reaction of the sensifacient 

 apparatus of the tactual and other species of cutaneous sense. In such 

 a supposition the belief is implicit, that a certain extreme degree of 

 excitement in a sensory centre produces pain. Pain on this view is but 

 a character or function common to various species or orders of sense, 

 and not a sensation of species apart and distinct from the reactions of 

 all other senses. On this view the sensations of each sense can among 

 themselves be different, not only in virtue of difference of intensity, of 

 quality (timbre, colour, etc.), of " local sign," etc., but also by difference 

 of " affective tone " in relation to agreeablenesss and disagreeableness. 

 Such an opinion is consonant with the general experience, that 

 sensations of every species, although in moderation pleasant, become 

 unpleasant when their intensity exceeds a certain degree. 



It can be said that lights, sounds, odours, tastes, cold, heat, etc., must, 

 considered as sensations, be " moderate " to be enjoyable. Of conditions that 



1 Meissner, " Beitr. z. Anat. u. Physiol, d. Haut," Leipzig, 1853. 



2 Vierordt, Ztschr.f. Biol., 1876, Bd. xii. S. 226. 



3 Hagen, " Psychol. Untersuch.," Braunschweig, 1842, S. 59 ; Lotze, "Med. Psychol.," 

 S. 233 ; Kiilpe, Vrtljschr. f. wisscnsch., Bd. xi. S. 424 ; Alf. Lehmann, "Die Hauptgesetze 

 d. Gefuhlslebens," Leipzig, 1892, S. 143; Wundt, "Grundziige d. physiol. Psychol.," 

 Leipzig, 1893. 



4 See, for instance, C. A. Strong, Psychol. Rev., N.Y. and London, 1894, vol. ii. p. 

 329 ; 1896, vol. iii. p. 64. 



5 See Miinsterberg, "Beitr. z. exper. Psychol.," No. 4 ; v. Frey, "Beitr. z. Physiol, d. 

 Schmerzsinnes," Ber. d. k. sacks. Gesellsch. d. Wisscnxch. zu Leipzig, rnalh.-phys. Classe, 

 July 1894, Dec. 1894, March 1895 ; Kiesow, Phil. Shtd., Leipzig, 1894, Bd. ix. ; and, with 

 reservations, Goldscheider, " TJeber den Schmerz," Berlin; and previous papers, Arch. f. 

 Physiol, Leipzig, 1885; Arch. f. Psychiat., Berlin, 1887; and " Ueber die Behandlung 

 des Schmerzes," Berl. klin. Wchnschr., 1896, No. 3. 



