It has been observed, in a general manner, that the lower races are not very sensitive to pain. Thus Negroes in Egypt endure, almost without suffering, the most extensive surgical operations (Pruner Bey), and Mantegazza (_op. cit._, chap. xxvi.) reports a large number of examples. In the peasant sensibility is usually less keen than in the town-dweller, and it may be admitted without hesitation that susceptibility to pain increases with civilisation; what is called stoicism should often be called a feeble degree of sensibility. Hyperalgesia is best seen in cases of extreme nervous over-excitement. In some it is generalised, constituting the “supplicium neuricum,” and the patient says that he is the prey of unspeakable torments. It is less frequent in the case of the special nerves, but is sometimes met. One suffers from the slightest noise, and cannot tolerate the least smell. Pitres quotes the case of a person who shut herself up in a dark room, only coming out at night with a thick shade against the rays of the stars. Those who entered her dark room during the day had to wear sombre clothes, completely concealing the shirt-collar, of which the white reflection was horribly disagreeable to her.[26] Cutaneous hyperalgesia is very common, sometimes extending over the whole body, sometimes disseminated in patches. Weir Mitchell, in his book on injuries of the nerves, reports numerous examples; among others, a wounded soldier to whom the mere crumpling of paper caused atrocious pain. Opium-smokers, when they interrupt their habits, feel the least breath of air as icy cold, and complain of intolerable pains in all parts of the body. Hyperalgesia of the deep tissues is also frequent among the hysterical and hypochondriacal. ----- Footnote 26: Pitres, _Leçons Cliniques sur l’Hystérie_, i. p. 182. ----- It must be remarked in passing that just as insensibility to pain (analgesia) is independent of incapacity to receive sensorial impressions (anæsthesia), so hyperalgesia is distinct from hyperæsthesia. The latter is a power of perception much surpassing the average; it is known that certain races and individuals possess extraordinary visual, auditory, or olfactive acuteness; the tactile hyperæsthesia of the blind is also known, and in hypnotised subjects the delicacy of the senses has sometimes seemed miraculous. Hyperalgesia then, like analgesia, shows that pain is relatively independent of the sensations which arouse it. III. We may conclude, from what goes before, that though physical pain (of which alone I am speaking at present) is always bound to an internal or external sensation, and forms part of a psychic complexus, it may be separated and disjoined. It has then its own conditions of existence, and we may, in advance, say as much for pleasure.