9 86 CUTANEOUS SENSATIONS. 



The lowest limina for pain are found in the temple 1 and the dorsal skin of 

 the finger-joints. 2 Next, perhaps, come the tongue-tip and the forehead. The 

 hand on the ulnar side is more sensitive for pain than on the radial. Glans 

 penis, buttock, ankle, are among the least. On the whole, the pelvic region is 

 as poorly sentient to pain as any part of the body surface, Flexor sides are, on 

 the whole, less sensitive than extensor in regard to pain. 3 The topography of 

 " pain " in the skin, as regards its degrees of delicacy, certainly differs much 

 from the topography of "touch," but the accounts yielded by various 

 observers with algesimeters of different kinds, are very discrepant. 4 The 

 following are Bernhardt'!? figures, obtained by his faradic method ; the figures 

 represent the distance of the secondary coil from the primary : — 



Tongue-tip . . 141 



Cheek . . .125 



Back . . .116 



Sternum . . . 114 



Buttock . . . Ill 



Thigh . . .102 



Back of hand . . 99 



Fore-arm . . . 93 



Instep . . . 92 



Pulp of finger . . 84 



Palm ... 75 



Toe-tip . . . 65 



Goldscheider has examined the regional distribution of heat-pain. 



2. The liminal intensity for electrical stimuli (break-induction shocks 

 applied by unipolar method) is higher for touch spots than for pain- 

 spots. 5 



It is impossible to say whether these electrical stimuli to the skin excite 

 the end-organs or the nerve fibres. The anomalies of the results of electric 

 excitation in various parts of the skin show clearly that the skin is not 

 equipped with organs adapted for such stimuli. In the palm, for the current 

 to suffice to excite touch, it must be applied at the mouths of the sweat glands. 6 



Liminal intensity of pain stimuli is highest where the skin is thick 

 and lies on thick muscle far from bone ; 7 this is with mechanical 

 stimuli, and where the local deformation is not well estimated. Palm, 

 thigh, and ankle, after temple, are parts where the limen is highest. 8 



3. Cooling the skin paralyses the pain spots sooner than the 

 touch spots, although causing preliminary hyperesthesia of both. 9 



Cocain locally applied to the tongue suppresses touch, taste, cold, warmth, 

 and pain sensations, the order of paralysis in time being earliest temperature 

 sensation, then taste, then touch, and finally pain. 10 According to Shore, pain 

 is suppressed before touch. 11 The statement 12 that cocain paralyses in the eye- 

 ball only the pain spots, is not confirmed. 13 The behaviour of cocain in 

 rendering the cornea analgesic, and yet allowing sensations of touch, though 

 impaired, is important for deciding the true position of pain from pain spots. 

 Carbolic acid, 14 in 5 per cent, solution on skin or tongue, acts in the same 

 way as cocain, but not so strongly. By subcutaneous injection in 2*5 



1 Harold Gifting, Psychol. Pen., N. Y. and London, Feb. 1895. 



2 0. Motschutkowsky, Neurol. Cenlralbl., Leipzig, 1895, Bd. xiv. S. 140. 



3 Hess, ibid., 1895, Bd. xiv. S. 548. 



4 The degree of yieldingness of the skin, by reason of whether it lies close on bone or 

 floats on muscle, etc., is of great influence (see H. Gifting, op. cit.; also, for other causes 

 of difference, Hens, op. cit.). 



5 v. Frey, op. cit. 6 v. Frey, op. cit. 7 Gifting, op. cit. 

 8 Gifting, op. cit. 9 v. Frey, op. cit. l0 Goldscheider. 



11 Journ. Physio/., Cambridge and London, 1892, vol. xiii. p. 207. The discrepancy 

 between Goldscheider and Shore may be reconciled by Kiesow's observation, that deep pain 

 disappears, but not surface pain (Phil. Stud., Leipzig, 1894, Bd. ix. S. 510), in the 

 mucosa of the lip. 



13 H. Donaldson, Mind, London and Ediub., 1885, vol. x. 



13 v. Frey, op. cit.; Nagel, op. cit. u Goldscheider, op. cit. 



