NORMAL PROCESSES OF ENERGY METABOLISM 577 



meter (can) and weighed in kilograms. An electrical device under the 

 control of an observer enables him to stop instantly the flow of water into 

 this meter upon the termination of a period by the second hand of a clock. 



Fig. 28. Diagram of the Atwater, Rosa, Benedict respiration calorimeter as 

 prepared by DuBois for the Sage Calorimeter. 



Ventilating System: 



2 Oxygen introduced as consumed by 

 subject. 



3, H 2 S0 4 to catch moisture given off by 

 soda lime. 



2, Soda lime to remove CO 2 . 



1, H 2 SO 4 to remove moisture given off 

 by patient. 



Bl, Blower to keep air in circulation. 

 Indirect Calorimetry: 



Increase in weight of H 2 SO 4 ( 1 ) = 

 water elimination of subject. 



Increase in weight of soda lime (2) + 

 increase in weight of H 2 S0 4 (3) = 

 C0 2 elimination. Decrease in weight 

 of oxygen tank = oxygen consump- 

 tion of subject. 

 Heat -Absorbing System: 



A, Thermometer to record temperature 

 of ingoing water. 



B, Thermometer to record temperature 

 of outgoing water. 



V, Vacuum jacket. 



C, Tank for weighing water which has 

 passed through calorimeter each 

 hour. 



W, Thermometer for measuring tem- 

 perature of wall. 



A,, Thermometer for measuring tem- 

 perature of the air. 



R, Rectal thermometer for measuring 



temperature of subject. 

 Direct Calorimetry: 



Average difference of A and B X liters 

 of water + (gm. water eliminated X 

 0.586) (change in temperature of 

 wall X hydrothermal equivalent of 

 box) (change of temperature of 

 body X hydrothermal equivalent of 

 body) = total calories produced. 



Th. thermocouple; Cu, inner copper 

 wall; Cu 2 , outer copper wall; E, F, 

 dead air-spaces. 



The average rise in temperature of the numerous readings which have 

 been taken during the period multiplied by the weight of the water gives 

 the amount of heat eliminated by radiation and conduction and carried 



