FASTING METABOLISM 53 



Loss of heat 



Per i kg. body weight : 36-6, 40-9, 45-9, 46-2, 65-2, 

 66-1, 88-1. 



Per i sq. cm. body surface : 1036, 1112, 1207, 

 1097, 1183, 1153, 1212. 



Reckoned upon I kilo body weight the smaller 

 animals used up far more heat than the large ones, 

 whereas when the calculation is made upon the loss 

 of heat from an equal body surface only small 

 differences are seen. It is thus possible to say that 

 the total exchange of energy, and with it naturally 

 the consumption of material, depend upon the 

 surface of the body. 



There is another factor that influences these re- 

 lations, and that is the surrounding temperature. In 

 an experiment two dogs, one of which (A) had long 

 hair and the other (B) was clipped, were kept at 

 different temperatures with the following results, 

 the loss of heat at 30 being taken as 100, and the 

 other temperatures calculated on that basis 



(A) (B) 



At a temperature of 30 C. 100 100 



20 C. 135 157 



10 C. 170 214 

 oC. 205 271 



It is thus seen that by warming the surrounding 

 atmosphere a considerable diminution in loss of 

 heat is obtained, for compared with o C. the 

 saving was 



