HUMAN RACIAL BESPONSES 



Indians. The subjects were in a basal state, and the measurements 

 were made on the subjects in their ownbeds immediately after they 

 had been awakened. 



The subjects exhaled through a rubber mouth piece, a one way 

 plastic valve, and a short length of nibber hose into the portable 

 MuUer-Franz respirometer described by Lehman (1953), and 

 Montoge et al. (1958). Aliquot samples of expired air, which were 

 about 0.3% of the total volume, were passed through Alcoa Alumina 

 desiccant in a 50 cc glass syringe into a Model C Beckman Oxygen 

 Analyzer. Expired air volumes at BTPS were reduced to STPD. 

 Heat production was calculated from the following expression by the 

 method proposed by Weir (1949): 



kcal/hr/m = 



V^ X (1.046 - 0.05% O E) X 60 

 2 E ' 2 ' 



S. A. 



where: 



V = minute volume of expired air 

 E 



%0 E = % oxygen in expired air 



2 

 S. A. = surface area in m 



Bath calorimeter. The thermoregulated recirculating water bath 



calorimeter constructed and previously described by Carlson (1961) 



was utilized. It was similar to that used by Burton (1936). The bath 



contained 396 liters of water, and its temperature could be regulated 



within ±0.1 C. The bath was installed in a room where the room air 



o 

 temperature could be controlled within ±1.0 C. Water temperatures 



o o o 



selected were 35 C, 33 C and 30.5 G, and room temperatures 



o 

 were maintained about 14 G lower to insure a constant rate of heat 



loss. Water and room temperatures were allowed to stabilize for 12 

 hours. The average amount of electrical energy required to main- 

 tain the water temperature in the calorimeter was measured at 6 



359 



