22 Journal of Comparative Neurology. 



trie reference of sensations of double contact, as when the blind 

 man seems to feel an object at the end of his cane, or the sur- 

 c^eon's sensation is transferred to the end of his probe. We 

 may dismiss, as beyond our limits, the three sciences — optics, 

 acoustics, haptics (the skin and muscular sensations) — and there 

 still remains a set of sensations which may be conveyiiently 

 grouped as general sensations, which bring us into closest rela- 

 tions with the lower special senses, olfaction and taste, and the 

 diffuse sensations on one hand, and subemotional processes, like 

 elation, ennui, and depression, where total sensations and rudi- 

 mentary feelings fuse. 



It must not be forgotten that pain and sense gratification 

 are strong elements in the emotions and require a careful exam- 

 ination. Hoeffding says " feeling stands out plainly, as an ele- 

 ment different from the actual sensation, in certain experiences, 

 which prove that the pain caused by an excitation takes longer 

 to be produced than the actual sensation, and that sensation 

 may arise without the corresponding feeling, and vice vefsa." 

 Richet says "pain without memory and without radiation 

 would be no pain at all." Often an interval of one or two sec- 

 onds may elapse after the sensation is perceived before pain 

 appears. These cases, so often quoted as proving the distinct 

 nature of pain, are in one respect fallacious. When a nerve- 

 fibre is penetrated by a pin the pain is nearly, if not quite, as 

 promptly felt as the touch. When the finger is struck by a 

 hammer the pain is frequently long delayed. But the acme of 

 pain in that case is due to a reactionary process in the tissues, 

 notably the vascular contractions, etc. There may be several os- 

 cillations of pain and a set of summations of a curious character. 

 It is even possible, by bringing to bear counter-irritants, to pre- 

 clude these after-effects and mitigate the pain, as by rubbing or 

 pinching the part. 



In the case of a burn the conductivity of the tissues and 

 vascular responses are even more evident, and such attempts to 

 differentiate pain from sensation as a modality of feeling are 

 futile. The fact that there may be analgesia without anaesthesia, 

 and vice versa, is tentatively explained by the recent suggestion. 



