Relations between Factors of Metabolism. 



221 



equivalent of carbon dioxide, it is necessary, of course, to bear in mind that the 

 carbon-dioxide production varies widely with the nature of the material burned. 

 With a carbohydrate-rich diet, therefore, where the storage of glycogen is 

 probably somewhat above normal, even during the period from 1 a. m. to 7 a. m., 

 or 6 to 7 hours after the last meal, there may still be an increased oxidation of 

 carbohydrate, and while normally several hours after the last meal one would 

 expect a subject to be living for the most part upon body fat, the results here 

 show that there may be a not inconsiderable amount of carbohydrate burned 

 during the sleeping period. The values in table 91 include all the experiments 

 that can be collected with each of these individuals in which the same periods 

 can be used to compute the calorific equivalents of both oxygen and carbon 

 dioxide. 



During waking hours. While admittedly the determinations of the oxygen 

 consumption during waking hours, especially with subjects not previously accus- 

 tomed to the routine of an experiment, present certain difficulties by reason of 

 the almost unavoidable differences in the muscular activity at the beginning 

 and end of the period, nevertheless in a large number of experiments the oxygen 

 consumption was determined simultaneously with the carbon-dioxide elimina- 

 tion and the heat production, and consequently we have computed and presented 

 in table 92 the calorific equivalents of both oxygen and carbon dioxide for a 

 large number of individuals during the waking hours. Included in this table 

 are also those who appeared in table 91 for the carbon-dioxide and oxygen 

 calorific equivalents during sleep. Many of the experiments continued for 

 several days, but a large number of them were experiments of short duration, 

 4 to 8 hours. In certain of these experiments likewise, the calorific equivalent 

 of oxygen could not be determined and only the calorific equivalent for carbon 



Table 92. Calorific equivalents of oxygen consumed and carbon dioxide eliminated 

 for different individuals during leaking hours in rest experiments. 



