ANIMAL HEAT. 



517 



Should the voluntary activities be at rest, the major portion of this 

 energy is transformed into heat. The same number of heat units 

 would be produced within the body as within the calorimeter,, pro- 

 vided the foodstuffs were completely oxidized. However, we know 

 that every gram of proteid yields one-third of a gram of urea during 

 combustion within the body. The urea has a heat value of its own, 

 so that the real number of heat units obtained by body-combustion 

 is considerably less than that of calorimeter combustion of proteids. 



R7T. 



108 



.07 



tc6 c 



103" 



Fig. 181. Bilateral Puncture of the Tuber Cinereum of Rabbit 

 Through Roof of Mouth. 



'he units obtained from body or tissue combustion represent a 

 'physiologic heat-value"; those gained from the calorimeter, a 

 'physical heat-value." 



A man produces daily a quantity of heat equal to about 2800 

 dories. 



Regulation of Temperature. That the regulation of the tem- 

 perature cannot be accomplished solely by the action of the circula- 

 tion, respiration, vasomotor, and sudorific centers, is shown by the 

 following facts: (1) If a puncture is made through the roof of the 

 mouth of a rabbit with a guarded dental drill and the tuber cinereum 

 is only slightly grazed, the animal will fall at your feet, dead, in five 



