162 



Metabolism of Healthy Man. 



hours, 1 a. m. to 7 a. m., there is the minimum muscular exertion, and food 

 had not been taken for several hours previously, there is no reason for believing 

 that the results are not truly representative of the normal carbon-dioxide pro- 

 duction of these individuals under the conditions obtaining inside the respira- 

 tion chamber. The subjects were cautioned not to move or uncover the body 

 before 7 a. m. even if, as occasionally happened, they awoke before that hour. 

 For convenience, the experiments are arranged in the order of the body-weights 

 of the subjects. The amounts of carbon dioxide excreted per hour vary from 

 19.4 grams to 27.5 grams. The average amount for 19 subjects during the 

 period from 1 a. m. to 7 a. m. is 23.4 grams per hour. 



Table 67. Carbon dioxide eliminated during sleep by different individuals, 



1 a. m. to 7 a. m. 



1 In computing body-surface the formula of Meeh has heen used : 12.312 Vbody-weight. 



A number of writers, instead of expressing the carbon-dioxide production in 

 grams per hour, have expressed it as cubic centimeters per minute, and in the 

 fifth column of table 67 the values obtained with these individuals expressed as 

 cubic centimeters per minute are given. The average carbon-dioxide production 

 per minute per person was 199 c. c. The lowest was 165 c. c. with the subjects 

 A. H. M. and H. L. K., and the highest 233 c.-c. with the subject H. A. 



Per kilogram of body-weight. Eesearches in metabolism show that there is 

 a distinct relationship between the body-weight of the subject and the metab- 

 olism, and as carbon dioxide is an index of the general metabolism it is im- 

 portant to compare experiments, not on the basis of individuals, but on the 

 basis of per kilogram of body-weight. Consequently, in the experiments here 

 reported, the calculations have been made per kilogram of body-weight per 

 hour, and they thus give a more scientifically exact comparison with different 

 individuals. The results are recorded in the sixth column of table 67. Gen- 







