OF SENSATION IN GENERAL. 387 



however, not only from abnormal activity of the circulation in the organ or 

 part itself, but from the same condition affecting that part of the sensorium in 

 which the impressions are received. Thus in active congestion and inflam- 

 mation of the brain, the most ordinary external impressions produce sensations 

 of an unbearable violence ; and there are some peculiar conditions of the 

 nervous system, known under the name of hysterical, in which the patients 

 manifest the same discomfort, even when the circulation is in a feeble, rather 

 than an excited state. It is remarkable that the sensibility of the mucous 

 membranes lining the internal organs, is less exalted by the state of inflamma- 

 tion, than is that of most other parts ; and in this arrangement we may trace 

 a wise and beneficent provision ; since, were it otherwise, the functions neces- 

 sary to life could not be performed without extreme distress, with a very 

 moderate amount of disorder in the viscera. If a joint is inflamed, we can 

 give it rest ; but to the actions of the alimentary canal we can give little volun- 

 tary respite. 



509. The feelings of Pain or Pleasure, which are connected with particular 

 sensations', cannot (for the most part at least) be explained upon any other 

 principle than that of the necessary association of these feelings, by an original 

 law of our nature, with the sensations in question. As a general rule, it may 

 be stated, that the violent excitement of any sensation is disagreeable, even 

 when the same sensation in a moderate degree may be a source of extreme 

 pleasure. This is the case alike with those impressions, which are communi- 

 cated through the organs of sight, hearing, smell and taste, as with those that 

 are received through the nerves of common sensation ; and there can be no 

 doubt that the final cause, or purpose, of the association of painful feelings 

 with such violent excitement, is to stimulate the individual to remove himself 

 from what would be injurious in its effects upon the system. Thus, the pain 

 resulting from violent pressure on the cutaneous surface, or from the proximity 

 of a heated body, gives warning of the danger of injury, and excites mental 

 operations destined to remove the part from the influence of the injurious 

 cause ; and this is shown by the fact, that loss of sensibility is frequently the 

 indirect occasion of severe lesions, the individual not receiving the customary 

 intimation that an injurious process is taking place. Instances have occurred, 

 in which severe inflammation of the membrane lining the air-passages has re- 

 sulted from the effects of ammoniacal vapours, introduced into them during a 

 state of syncope, the patient not receiving that notice of the irritation, which 

 would, in an active condition of his nervous system, have prevented him from 

 inhaling the noxious agent. 



a. The following case, recorded in the "Journal of a Naturalist," affords a remarkable 

 instance of this general fact. The correctness of the statement having been called in question, 

 it was fully confirmed by Mr. Richard Smith, the late senior surgeon of the Bristol Infirmary, 

 under whose care the sufferer had been. "A travelling man, one 'winter's evening, laid 

 himself down upon the platform of a lime-kiln, placing his feet, probably numbed with cold, 

 upon the heap of stones, newly put on to burn through the night. Sleep overcame him in 

 this situation ; the fire gradually rising and increasing, until it ignited the stones upon which 

 his feet were placed. Lulled by the warmth, the man slept on ; the fire increased until it 

 burned one foot (which probably was extended over a vent-hole) and part of the leg above 

 the ankle entirely off, consuming that part so effectually, that a cinder-like fragment was 

 alone remaining, and still the wretch slept on! and in this state was found by the kiln-man 

 in the morning. Insensible to any pain, and ignorant of his misfortune, he attempted to rise 

 and pursue his journey, but missing his shoe, requested to have it found; and when he was 

 raised, putting his burnt limb to the ground to support his body, the extremity of his leg-bone, 

 the tibia, crumbled into fragments, having been calcined into lime. Still he expressed no 

 sense of pain, and probably experienced none ; from the gradual operation of the fire, and his 

 own torpidity during the hours his foot was consuming. This poor drover survived his mis- 

 fortunes in the hospital about a fortnight ; but the fire having extended to other parts of his 

 body, recovery was hopeless.'' 



