182 Metabolism of Healthy Man. 



Using the Zuntz-Geppert apparatus, Magnus-Levy, studying a man who had 

 been fasting for some time, records a number of observations when the man 

 was asleep. 1 From 9 h 45 m p. m. to 10 h 30 m p. m. the subject is reported as 

 having been asleep, and the oxygen consumption during this time was 207.7 

 c. c. to 219.4 c. c, the average being 212.2 c. c. per minute. Again, from 1 a. m. 

 to l h 41 m a. m. he was in part dozing and the oxygen consumption averaged 

 209.2 c. c. per minute. From 4 h 16 m a. m. to 4 h 40 m a. m., 2 experiments, when 

 he was partly asleep, showed an oxygen consumption of 225.8 c. c. 



Although direct statements as to the amount of sleep are lacking, in the ex- 

 periments made by Laves 2 with the Hoppe-Seyler respiration chamber there were 

 2 experiments which were reported as having been made between 9 p. m. and 7 

 a. m., and it is highly probable that the subjects were asleep, although the sleep 

 may not necessarily have been profound. The oxygen consumption during these 

 two periods averaged 21.2 grams and 21.3 grams per hour, respectively. 



In 1 experiment reported by Jaquet 3 in the original description of his appa- 

 ratus, the subject was in the respiration chamber from 7 p. m. until 3 a. m., 

 and it is highly probable that the values from 12 midnight until 3 a. m. were 

 during sleep. The oxygen consumption during these 3 hours was 28.4, 27, and 

 23.7 grams, respectively. 



Staehelin, using this same apparatus, made a number of experiments, all 

 during the night. The results have been abstracted on page 178 of this report. 



It is thus seen that there are but few experiments during sleep with which 

 the results here presented can be properly compared. Since, however, we find 

 such marked concordance between the results for the carbon-dioxide production 

 obtained during the sleeping period with a large respiration chamber and the 

 results obtained on subjects with complete muscular rest with the Zuntz-Geppert 

 apparatus, it may be of interest to compare the results here obtained on sleeping 

 man with those obtained on the resting man with complete muscular rest and 

 12 hours after the last meal. These results are given on page 156 of this 

 report. By reference to this table it can be seen that the average oxygen con- 

 sumption of the 19 subjects was 237 c. c. per minute, while with the subjects 

 asleep, the average was 249 c. c. per minute. Per kilogram of body-weight per 

 minute, the average of 19 subjects with the Zuntz-Geppert apparatus was 

 3.79 c. c. as against 3.75 c. c. with the sleeping subjects reported by us. The 

 oxygen absorption per square meter of body-surface with the subjects with the 

 Zuntz-Geppert apparatus was 121.7 c. c. as against 123 c. c. with the subjects 

 asleep. The agreement is very striking in all the comparisons. 



Influence of Previous Muscular Activity upon Oxygen Consumption 



during Sleep. 



In several of the experiments here reported, it is possible to study the oxygen 

 absorption during sleep following different degrees of muscular activity, some- 



1 Magnus-Levy, Archiv f. die ges. Physiol., 1894, 55, p. 35. 



2 Laves, loc. cit. 



s Jaquet, loc. cit. 



