On the Mechanism of Chemical Temperature Regulation. 207 



being warmed, or that the vigour of the regulation was different, i.e. the 

 amount of extra oxygen resulting from a given lowering- of the skin 

 temperature had altered. As a result the first and second half of the 

 experiment are not in agreement. The first of these cases is illustrated by 

 fig. 4. 



This significance of the body temperature having been recognised, an effort 

 was made to determine if this influence could be localised. Probability pointed 

 to the temperature of the brain being of special importance, and in fact it 

 was found possible to completely stop shivering and lower the oxygen 

 consumption by heating the blood going through the carotids (by Kahn's 

 tubes) (23). This is illustrated by the following extract from a protocol : — 



Babbit, 1700 grm. 



Time. 



Oo consump- 

 tion c.e. 

 per 10 min. 



Eeetal 

 tempera- 

 ture. 



Skin 

 temperatures. 



Temperature 

 of fauces. 



Remarks. 



4.49 



187 



o 



31 6 



o 



30-1 



31 -1 



o 



31 -2 



Shivering. 



» 



Shivering very faint. 



4.54 



197 



31 -6 



30 



31 4 



34 



5.3 



128 



31 -8 



30 4 



31 "8 



36 



5.12 



158 



32 -1 



31 -2 



32 3 



36 -9 



Shivering, which had in- 

 creased, has stopped. 



5.20 



98 



32 -3 



30-4 



33 



38 -4 



No shivering. 

 Shivering recommences. 



5.28 



113 



32 -1 



30 -8 



32 -9 



36 -7 



5.32 











36 -1 



5.35 



128 



32 



31 



32 -4 



34 -3 



Shivering. 



5.40 



144 



32 



31 



32 -4 



32 



;» 



5.47 



165 



31 -7 



31 



32 -3 



31 -2 





5.54 



133 



31 -2 



31 2 



31 4 



31 





It was hoped by this means that a double series of observations with and 

 without shivering at various rectal temperatures could be obtained, thus 

 avoiding the necessity for obtaining the second figure by extrapolation. 

 A number of such attempts failed on technical grounds. It was found very 

 difficult to get a complete experiment of this type, especially when as was 

 the case the brain temperature was also determined by a thermocouple 

 introduced through the skull. In one experiment I was, however, able to 

 show that shivering ceased at the same brain temperature whether this was 

 reached by ' locally heating the head blood or warming the body of the 

 animal in the bath. The following shows the essentials : — 



