40 August Krogh and Marie Krogh. 



CO2, corresponding to the protein catabolism from the totals for these 

 gases we have calculated the R. Q. of the non protein metabolism and 

 from this and the oxygen the heat produced, using the table of re- 

 spiratory quotients and corresponding caloric values of oxygen given 

 by ZuNTZ ^. ZuNTz's table covers only the respiratory quotients 

 between 0.7 and 1.0, but we have observed in a series of periods in 

 exp. II that the respiratory quotient of the non protein metabolism 

 rose above unity indicating a formation of fat from carbohydrate. 

 In these cases we have extrapolated the caloric values of the oxygen 

 from ZuNTz' table, but we are fully aware that the resulting figures 

 for total metabohsm cannot be very accurate. 



Table 7 shows the average intake of calories with the food and 

 the corresponding metabolism and N excretion per day for each sub- 

 ject. The food is calculated for days 

 Table 7. Energy balance in reckoned from midnight to midnight and 

 24 hour periods. no reduction has been made for the 



Experiment II. calories lost with the feces. The figures 



for catabolic heat production and excre- 

 tion of N are for days reckoned from 2 

 p. m. to 2 p. m., which will correspond 

 well to the period of absorption and 

 catabolism of the food. In exp. II the 

 food has on all days been in excess of 

 the requirements 2. In exp. Ill there 

 has been an excess only on the first 

 day, and in exp. IV the food has on all 

 days been insufficient. The metabolism 

 is low in all cases as might be expected 

 from the confinement and the small 

 amount of muscular work done. The 

 production of heat is lower in exp. II 

 than in exp. IV in the same subjects in 

 spite of the abundant food in the former 

 exp,, but this is easily explicable from the difference in work per- 

 formed. There is no clear evidence in the figures for 24 hours meta- 

 bolism of any specific dynamic action of the protein in the diet. 



When we consider the separate 8 hour periods we find fairly low 

 and uniform figures for the metabolism during the 8 hours when the 

 subjects were asleep or at all events generally lying down and at- 

 tempting to sleep. 



1 ZuNTz & Loewy: Lehrbuch d. Physiologie, 1909, p 663. 



2 For the third day in exp. II the resp. exch. of the last period 6 — 2 was not 

 available. The figure for the corresponding period of a previous day (^^/7 6 — 2) 

 has been utilized. In exp. IV the amount of food taken on the first day is not 

 exactly known. It has exceeded 700 Cal. but cannot have been more than 1200. 



