I.— PHYSIOLOGY 195 



suggested to us this would be a reason for the evolution in the body of 

 the power to manufacture the ferment glutathione, which is otherwise 

 without a clear explanation. 



The Measured Heat at High and Low Quotients. 



If it is assumed that the reaction represented by the reversible equation 2 

 — carbohydrate to fat conversion — takes place at high and low respiratory 

 quotients while the combustion of carbohydrate and fat in a fixed ratio 



-xg. 



»« 



-10* 



-al 





o '^ « ' « . ?■"<■ 1 f'i *"! - " X " 



, » <<, X JL ^ Ja^ i — j • ; — a — I rf- 



' 5' ^'x" 



X X 



-107. 



-20X 



-3<a 



xS KTT Xi, * X 



X S* « „ S* "x 



' « . ' . ' 5 '^ X , « 



-Ba. I I L 



so -as 



9S 



Fig. 4. — Comparison of indirect and direct calorimetry on the theory of the 

 constant combustion ratio. Error due to conversion at low and high quotients. 

 Du Bois's results. 



Ordinates : Percentage differences between measured heats and heats calcu- 

 lated from CO2 output. Abscissae : Respiratory quotients. 



is taking place simultaneously ; the measured (direct) heat should be less 

 than the heat calculated from the carbon dioxide output, by equation i, at 

 high quotients, since the measured heat will be the resultant of the heat 

 given out from combustion less the heat absorbed in the conversion of 

 carbohydrate to fat. At low respiratory quotients, when the reverse 

 process takes place, the measured heat should be greater than the heat 

 calculated from the carbon dioxide output. 



For the construction of fig. 4 the heat was first calculated from the 

 carbon dioxide output for each of Du Bois's 377 observations by the 

 regression equation i. The difference between the heat calculated in 

 this manner and the corresponding measured heat expressed as a 



