ALTERATION OF NERVE FIBRES AND CAPILLARIES, &C. 337 



and by reflex action to the extensive and widely- 

 distributed nervous derangement which usually at- 

 tends serious inflammations and general fevers. In 

 both classes of diseases the characteristic general 

 disturbance is due entirely to changes in the capillary 

 vessels and in the nerves of the capillary vessels, 

 the arrangement of which has been described. 



314. Alteration of nerve fibres, and capillaries in 

 chronic disease. The condition of health is dependent 

 upon the integrity of the nerve fibres distributed to 

 the capillary vessels. It is therefore of the utmost 

 importance to do all we can to keep these delicate 

 nerve fibres in an active state. By exercise, cold 

 bathing, and external rubbing, that amount of activity 

 of the nerve fibres and change in the capillary circu- 

 lation is ensured at least once in the twenty-four 

 hours that is required for keeping the nerve mechanism 

 which has been described in good order and activity. 

 These nerve fibres are, as it were, the sentinels which 

 give the earliest information of the dangerous proxi- 

 mity to the vessels of matters the entrance of which 

 into the blood might occasion serious disease or cause 

 death. So long as these sentinels are active and in 

 good working order, warning is given in time for 

 the performance of acts which prevent the ingress of 

 deleterious substances ; but if they act sluggishly, or 

 if the excitability of these nerve fibres is numbed by 

 certain agents, time is allowed for the poison just 

 outside the vessels to make its way into the blood : 

 while if they are paralysed, even temporarily, the 

 state of things is far worse. No watch is kept, and 

 the organism maybe destroyed by an invading poison 

 that under other circumstances might have been 

 effectually excluded. 



In many forms of chronic disease the nerve fibres 

 distributed to the capillary vessels, as well as those 

 ramifying upon the small arteries and veins, de- 

 generate and are at length destroyed. So that the 



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