1904.] Heat Regulation and Death Temperatures. 



373 



the latter. It may be that for this reason, there is a slow rise of 

 temperature in some diseases; while in others of more severe onset, 

 there is a sudden elevation of temperature, which may be due to 

 paresis of the higher centres. Septic conditions show frequently 

 changes of death temperature, which may be the result of : — 



1. Stimulation of the higher centres over the lower, producing fall of 



temperatures. 



2. Paralysis of the higher centres over the lower, producing rise of 



temperatures. 



3. Simultaneous paralysis of higher and lower centres producing no 



change. 



4. Special poisons may affect higher and lower centres differently. 

 There seems to be some evidence, therefore, in favour of the view 



that a higher centre in the brain controls the thermogenetic centres in 

 the spinal cord, but it does not follow, when there is an increased 

 heat production through the removal of this control, that there must 

 necessarily be pyrexia. An increase in the loss of heat may keep the 

 temperature at the normal level. In patients, however, who are dying, 

 there is a tendency for the amount of heat lost to be diminished, the 

 evidence for which has been pointed out above. Besides this natural 

 tendency, means are constantly employed to prevent falls of tempera- 

 ture in the failing, by increasing the amount of bed-clothes, by using 

 hot bottles, by bandaging the limbs before operation, etc. This 

 slight diminution in the amount of heat lost may be able to prevent 

 the temperature of the body falling, but it would hardly be sufficient to 

 raise it many degrees without some increase in heat production. From 

 these considerations it would appear that the variations in bodily 

 temperature as death approaches must be dependent in many instances 

 upon the increased amount of heat production and not upon the dimi- 

 nution of heat lost. As these variations are so constant, there is an 

 indication that, although the centre which controls thermolysis, heat- 

 loss, may be the chief factor in keeping the body at a normal tempera- 

 ture, yet the centre which controls thermogenesis plays a more 

 important part than has lately been attributed to it. 



The thermolytic centre probably has an inhibitory effect upon the 

 vasomotor centre, i.e., over vaso-constriction, in a similar manner, we 

 think, to the action of the upper thermogenetic centre upon the lower 

 in the spinal cord. As the lower thermogenetic centres tend to 

 exaggerate the amount of heat produced in the tissues, so the vaso- 

 motor centre by constricting the vessels tends to diminish the amount 

 of heat being lost; the latter effect being counterbalanced by the 

 inhibitory action of the thermolytic centre. The action both of the 

 lower thermogenetic centre and also of the vasomotor centre, when not 

 controlled by the higher centres, seems to be that of raising the bodily 

 temperature. 



VOL. LXXIII. 2 D 



