GASEOUS METABOLISM DURING REST. 499 



the values on October 7 and November 4 as basal values, we find here a 

 fall of approximately 11 per cent in the heat production per kilogram 

 of body-weight and about 9 per cent per square meter of body-surface. 

 Of particular interest in this connection is the fact that these low 

 values were found with Squad B on practically the first day on which 

 they returned from their Christmas vacation. This is in distinct 

 contrast to the values found with Squad A, which showed that both 

 the pulse-rate and, as will subsequently be seen in the general basal- 

 metabolism tables, the metabolism was considerably increased with 

 all the men after returning from their vacation. This low caloric 

 production of Squad B requires a critical examination of the metabolism 

 measurements on this particular night. 



In our effort to secure basal metabolism we have selected and re- 

 ported in table 114 the values representing the minimum carbon- 

 dioxide production per hour throughout the night. Most of the 

 periods of experimentation throughout the night were from a half hour 

 to an hour in length, and the values for the carbon-dioxide production 

 here given are based upon the average of two or three and frequently 

 more periods. Since there is, however, some discrimination per- 

 mitted in the selection of the minimum period and an error in selec- 

 tion might profoundly affect the low value found, we have computed 

 the average carbon-dioxide production for the measurements made 

 throughout the night. The values for the minimum carbon-dioxide 

 production per hour given in table 114 are naturally somewhat lower 

 than the averages found for the entire night, being usually not far from 

 5 to 10 grams.^ Thus, on the night of October 6-7 the total average 

 carbon-dioxide production for Squad B was 297 as against a minimum 

 of 292 gm. ; on November 3-4, 297 as against 295 gm. ; on November 

 17-18, 299 as against 292 gm.; on December 15-16, 296 as against 287 

 gm. ; and what is of special interest, on the night of January 5-6, 276 

 as against 265 gm. Under these circumstances, it is perfectly clear 

 that the value of 265 gm. is a probable minimum value and not an 

 erroneous selection based upon one or two periods. On account of the 

 construction of the group chamber and the fact that duplicate weighings 

 are made in each period, there is almost no possibility of an error in the 

 determination. Evidently, not only the minimum value but also the 

 total carbon-dioxide production was at a distinctly lower level on this 

 night than it had been on the previous occasions. Since the total body- 

 weight of the group varied only from 805 to 818 kg., the values for the 

 total carbon-dioxide production per hour on the different nights may 

 properly be compared. An examination of the original protocols for 

 this night shows no reason whatever for questioning these results. 



Among other explanations for this variation in metabolism found 

 with Squad B we have considered the change in temperature environ- 



^For detailed values of a typical night, see table 5, page 119. 



