Oxygen Consumption. 



185 



Per kilogram of body-iveight. Computing the results on the basis of per 

 kilogram of body-weight per hour, we find that the maximum oxygen con- 

 sumption per hour was with the subjects B. N. and J. W. H., 0.531 gram, 

 and the minimum 0.323 gram with the subject G. E. H. The average of all 

 the experiments showed 0.425 gram of oxygen absorbed per kilogram of body- 

 weight per hour. These figures correspond to 6.18 c. c. with B. N. and 6.20 c. c. 

 with J. W. H., and 3.77 c. c. with G. E. H. The average of all the experiments 

 showed 4.96 c. c. per kilogram of body-weight per minute. 



Per square meter of body-surface. Dividing the total amount per hour by 

 the area of body-surface, computed by the formula of Meeh, we find that the 

 absorption of oxygen per square meter of body-surface per hour varied from 

 a maximum of 17 grams with the subject J. W. H. to 10.5 grams with G. E. H. 

 The average of all the experiments showed 13.7 grams of oxygen absorbed per 

 square meter of body-surface per hour. 



The corresponding figures on the basis of cubic centimeters per minute showed 

 a maximum of 198 c. c. with the subject J. W. H. and a minimum of 122 c. c. 

 with the subject G. E. H. The average of all the experiments showed that there 

 were 160 c. c. of oxygen absorbed per square meter of body-surface per minute. 



The measurement of the oxygen absorbed by the body is of immense physio- 

 logical value with reference to the energy production, and with regard to the 

 apportionment of the katabolism between protein, fat, and carbohydrate. Sub- 

 sequent discussion, in which the relation between the carbon-dioxide excretion, 

 oxygen consumption, and the heat production is considered, will bring out these 

 points more clearly. 



RATIO OF OXYGEN CONSUMPTION DURING SLEEP TO THAT DURING WAKING HOURS. 



As was seen by comparing the carbon-dioxide production during sleep to 

 that in waking hours, there was a very considerable increase during the waking 

 period over sleep, even although there was no measurable external muscular 

 work performed. A comparison of the oxygen consumed during sleep with 

 that consumed during waking hours at rest is presented in table 74, the 



Table 74. Ratio of oxygen consumed during sleep to that consumed during waking 



hours in rest experiments. 



