148 



Metabolism of Healthy Man. 



is resting quietly in a respiration chamber with a relative humidity inside the 

 chamber not far from 50 per cent. Under these conditions 35 per cent of the 

 total water vaporized is computed as having been vaporized from the lungs. 



Table 57. Proportions of total water vaporized from the lungs and skin, 

 respectively, during sleep after rest. 



RATIO OF WATER VAPORIZED DURING SLEEP TO WATER VAPORIZED DURING 



WAKING HOURS. 



The general state of lowered metabolism obtaining during sleep would be 

 expected to have an effect upon the vaporization of water, consequently it is of 

 importance to compare the water vaporized during sleep with that vaporized 

 during the waking hours. The average results for 17 subjects have been col- 

 lected in table 58, in which are shown the water vaporized per hour during 

 sleep and the water vaporized per hour during the waking hours. 



Table 58. Ratio of water vaporized during sleep to that vaporized during leaking 



hours in rest experiments. 



Subject. 



W\ O. A. 



D. W. .. 

 J. C. W. 

 H. C. K. 

 H. F. ... 

 A. L. L. 



A. W. S. 



E. O. . . . 

 N. M. P. 



B. F. D. 



(a) 



Amount 



per hour 



during 



sleep. 



Gi 



ams. 



34.9 

 27.7 

 36.2 

 30.3 

 30.9 

 35.4 

 33.5 

 38.1 

 29.9 

 3S.9 



(b) 



Amount 



per hour 



during 



waking 



hours. 



Grams 



36.3 

 36.2 

 36.7 

 35.4 

 29.7 

 34.9 

 35.7 

 36.5 

 3S.2 

 44. S 



(c) 



Ratio 



sleeping 



to awake. 



(b+a) 



100:104 



131 



101 



U7 



96 



99 



107 



96 



128 



115 



Subject. 



(a) 



Amount 



per hour 



during 



sleep. 



(b) 



Amount 



per hour 



during 



waking 



hours. 



(c) 



Ratio 

 sleeping 

 to awake. 



(ft-i-a) 



C. R. Y 



J. F. S 



A. H. M 



H. R. D 



S. A. B 



H. E. S 



H. L. K 



Average . . 



Grams. 



44.5 

 3).9 

 25.4 

 25.1 

 26.9 

 29.2 

 2S.6 



32.1 



Grams. 

 38.0 

 35.6 

 29.0 

 25.7 

 26.7 

 27.3 

 34.9 



34.2 



100: S5 

 115 

 114 

 102 

 99 

 93 

 122 



ioo: lo- 



in this series of experiments, in which the muscular conditions were prac- 

 tically the same, i. e., no external muscular work, the water vaporized during 

 the waking hours when the subject was quietly sitting reading or writing was on 

 the average slightly greater than that vaporized when the same subject was lying 

 asleep, with light covering, the ratio of the amount vaporized during sleep to 

 that during the waking hours being on the average as 100 : 107. It could be 

 noted, however, that with 6 out of the 17 subjects the water vaporized during 

 waking hours was actually less than during the night. 



