Oxygen Consumption. 



183 



what on the plan already discussed under the head of the carbon-dioxide produc- 

 tion with similar conditions. These results are given in table 72. Under 

 ordinary conditions, when sleeping after rest with food, B. F. D. absorbed 19.5 

 grams of oxygen per hour. Sleeping after severe muscular work, when the 

 external muscular work amounted to the equivalent of about 420 calories, the 

 oxygen absorption was 22.4 grams per hour. With A. L. L. the quantities 

 after rest were 22.2 grams and after severe muscular work 23.9 grams, with a 

 maximum of 27.3 grains per hour after severe muscular work extending from 

 8 a. m. to 3 a. m. 



Table 72. 



Oxygen consumed during sleep (1 a. m. to 7 a. m.) 

 following different conditions of activity. 



1 Heat equivalent of work clone 420 calories. 



2 Heat equivalent of work clone 450 to 460 calories. 



3 Heat equivalent of work done 957 calories. Period of sleep. 4 a. m. to 7 a. m. 



Unfortunately, no experiments, aside from those made during short periods 

 with the Zuntz-G-eppert apparatus, throw much light upon the consumption 

 of oxygen following severe muscular work. The results here reported would 

 seem to imply that there was a distinct oxidation of material which continued 

 for some time after the cessation of work, and therefore we are inclined to 

 believe that the increased carbon dioxide noted was not due to a sweeping out 

 of carbon dioxide previously formed, but that it was due primarily to increased 

 metabolism resulting from the after-effect of the muscular work. 



The influence of severe muscular work on the subsequent metabolism and the 

 role that it plays in the process of recuperation after large drafts upon body- 

 material are problems that would seem to justify extended investigation. 



OXYGEN CONSUMPTION DURING WAKING HOURS. 



The oxygen consumption has now been measured in the respiration calorim- 

 eter with 51 different subjects. Many of the experiments covered a considerable 

 period of time and, indeed, with some subjects, were repeated several times. 

 In others, the observations were confined to but 2 or 3 hours during 1 experi- 

 ment. The results have been brought together in table 73, also arranged 

 in order of the decreasing body-weight. Here, again, we deal with conditions 

 of rest when the subjects are sitting quietly in the respiration chamber for the 

 greater part of the time, and as may be expected, the results are somewhat 

 greater than those found during sleep. The maximum oxygen absorption per 

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