PAIN. 353 



of little or no sensibility ; but when irritated, inflamed, or organically 

 diseased, they become more or less acutely sensitive ; just as the 

 common sensibility, and even the special sensibility, manifested by 

 the organs of animal life, may, when unduly exalted, give rise to pain. 

 Pain is a necessary consequence of sensibility ; and almost every 

 tissue or organ, when inflamed, gives rise to a peculiar pain. Painful 

 sensations, however, are frequently not precise. They are often er- 

 roneously localized, especially in cases of diseases of parts not ordi- 

 narily sensitive. The radiation of severe pains is a familiar fact, and 

 the irradiated pains are often more severe than those in the seat of the 

 primary irritation ; for the latter may even cease from exhaustion of 

 the nerves. Pain also renders nerves incapable of reaction under 

 normal stimuli. 



Pain is as old in the world as the existence of a sensory nervous 

 apparatus. The gift of sensibility is necessarily accompanied by a 

 liability to pain. The tension of the nervous energy connected with 

 feeling is, as it were, adapted to certain ranges of strength in the 

 stimuli which excite sensation ; and such an adaptation necessarily 

 implies that when the limits of agreeable stimulation are exceeded, 

 pain is the result. According to this view, pain is a necessary evil 

 under the existing relations between the nervous system and external 

 agencies. But, happily, pain itself cannot be conceived by the imagi- 

 nation, nor recalled by any effort of the memory, and is, for the most 

 part, transitory. Considered teleologically, pain has a beneficent ac- 

 tion, surpassing that of pleasure, which may, through uncontrolled 

 appetite and desire, lead to the undue use, that is, to the abuse, of 

 the various functions. Pain, moreover, is conservative, suggesting the 

 necessity for moderation and caution in the exercise of the functions 

 both of animal and vegetative life. Pain also is preservative, creating 

 a feeling of alarm and a sense of danger by exciting through nervous 

 sympathy, or through the blood, other organs or distant parts of the 

 system. Thus pain in a single part excites general febrile disturb- 

 ance, and so the whole system may be said to take warning. Pain 

 also forms a chief consideration in the symptomatology and diagnosis 

 of disease, which may thus be detected and combated in time to save 

 life. The importance of pain in morbid processes is recognized in the 

 term dis-ease, the obvious etymology of which is, as we ordinarily pro- 

 nounce the word, forgotten. Pain is, moreover, the cause of wide sym- 

 pathies between individual persons ; fellow-suffering excites human 

 charity and beneficence. It is to be noted that, in the ordinary act of 

 dying, the sensitive portion of our frame, or the sensorium, dies before 

 the merely motor apparatus, with its excito-motor or non-sensitive ner- 

 vous centres ; and thus the senses are subdued, and, as it were, anni- 

 hilated, sometimes long before the last breath is drawn. Finally, it 

 may be not unworthy of note that whilst limited suffering is the in- 

 evitable lot of sensitive animals, the relief of that suffering by nar- 

 cotic and anaesthetic agents, such as henbane, opium, ether, or chloro- 

 form, ordinarily necessitates the co-operation of substances derived 

 directly or indirectly from the vegetable kingdom. 



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