A STUDY IN MORBID AND NORMAL PHYSIOLOGY. 



249 



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compensates for the effect of the alteration of the circulation upon the heat prod 

 tion, but in fever, if there be already inhibitory heat paralysis, this compensating 

 influence disappears and consequently the reduction in heat production is exa^.reit 

 ated. However this may be, and 1 do not attach much importance to the ^&nit, 

 the proportionately excessive increase of heat dissipation in fever after section of 

 the cord plainly indicates that tlie general vaso-motor nerves restrain heat dissipa- 

 tion more completely in fever than in health and that consequently the effect of 

 their sudden palsy is more marked. It would appear, therefore, that an answer to 

 the first question has been reached. 



In looking for an answer to the second question I have availed myself of the 

 depression of temperature produced by irritating a sensory nerve. It has been 

 previously shown, that, precisely as the influence of peripheral irritations upon 

 blood pressure is a test of the integrity of the vaso-motor system, so is the effect of 

 similar irritations upon bodily temperature a test of the integrity of the inhibitory 

 heat system. 



The two following experiments prove that in fever gnlvanization of a sensitive 

 nerve is able to depress the temperature. If, as contended, this depression of 

 temperature is a test of the integrity of the heat inhibitory nervous system, the 

 conclusion is reached that at least in the two cases of pya^mic fever experimented 

 upon there was not palsy of the so-called inhibitory heat centre.* 



EXPEEIMEKT in. 



A moderate sized male cat. 



Time. Temp. REMARKS. 



(Fah.) 



10 A. M. 101O.5 Injected one fluid-ciraclim of pus into the flank. 



4:20 p. M. 106..5 

 4:40 Abdomen opened in linea alba and tlierniometcr inserted into the abdominal 



cavity ; temperature during the remainder of the experiment taken 



from it. 

 4:45 106 

 4:.53 In cutting down for tlie femoral nerve an artery was wounded, and abdut 



^ f. oz. of blood was lost. 

 4:5.5 103 



4:59 103 Current of moderate strength applied to nerve for about half a minute. 



5 102 5 



5:5 102 



5:15 Current applied for a brief space. 



5:20 101 



5:24 100.75 A very strong current applied for three-cpiarters of a minute. 



5:25 100.75 



5:26 100.25 



5:29 100.5 



5:30 Very strong current applied to nerve for about a minute. 



5:31 100 



5:33 100 



5:34 99.75 Cat killed. 



* The term inhibitory heat centre is used for brevity, and not as denying tlie theory that this 

 centre is really a vaso-motor centre for the muscles. 



32 October, 1880. 



