42 THE TONER LECTURES. 



vidual case. Now, with seemingly as little reason, sometimes 

 the materies morbi expends its force upon the inhibitory chem- 

 ical centre, and overwhelms it, paralyzes it; a general and rapid 

 rise of temperature results. The pain and sensibility in the 

 joints disappear, not because the disease has left the articula- 

 tions and attacked the brain, but because sensibility is every- 

 where destroyed by the heat, as is shown by the fact that in 

 the case here reported, just so soon as the heat was abstracted 

 and the general sensibility restored, the pain and tenderness 

 reappeared in the joints. 



The mode of origin of an ordinary case of irrilative fever is 

 rendered very evident by a knowledge of the inhibitory chemi- 

 cal centre. A boil, a pneumonic lung, or any local focus of 

 irritation, sends an impulse up an afferent nerve to the inhibi- 

 tory chemical centre. Perhaps, at first, this inhibitory centre 

 is excited to action, and the animal heat is reduced, and a 

 chill is caused. If the irritation be more persisting, the inhi- 

 bitory centre is weakened or paralyzed, and an elevation of 

 temperature results. 



The complete analogue of this exists in the case of the ordi- 

 nary motor nervous system. One irritation to a nerve results 

 in the production of a distant spasm ; another in the produc- 

 tion of a distant paralysis ; in other words, just as a peripheral 

 irritation may produce reflex functional excitement or reflex 

 functional depression of a motor centre, so may it cause a 

 reflex functional excitement, or a reflex functional depression 

 of this heat-centre; the difference being, that whilst in the 

 former instance there is a spasm or a paralysis, in the latter 

 there is a chill or a fever. 



It is well known that the slightest splinter will sometimes 

 cause the most intense motor disturbance ; hence it is not 

 strange that the irritation caused by the passage of a catheter 

 should produce an intense disturbance of the inhibitory heat- 

 centre, and consequently of the production of animal heat. 



