Water Vaporized from Lungs and Skin. 143 



The wide discrepancies noted in table 54 are here conspicuously absent, for 

 the extreme range in the results for the water vaporized per hour is only from 

 25.1 grams with H. E. D. to 44.5 with C. E. Y. The latter value is unusually 

 high, but 4 experiments with this subject gave practically the same results in 

 all cases. The average output of water-vapor is 32.1 grams per hour. Com- 

 puted on the basis of per kilogram of body-weight, the variations are from 

 0.36 with D. W. to 0.68 with C. E. Y., and the average value is 0.48 gram. 

 Per square meter of body-surface the water vaporized per hour ranges from 

 12.4 grams with D. W. to 22.2 grams with C. E. Y., the average value being 

 15.9 grams. 



COMPAKISON WITH OTHER INVESTIGATIONS ON WATER VAPORIZED DURING SLEEP. 



While from the conditions under which these experiments were made, it is 

 difficult to compare them with the results of other experiments, it may be of 

 interest to see in how far our results confirm those obtained previously. 



Lewin, 1 using the Pettenkofer chamber in Munich, made 5 experiments on 

 the water-vapor output of man while asleep. The amounts per hour were 22.9, 

 32.5, 28.7, 31.1, and 31.7 grams, respectively. In these experiments, however, 

 no notes were made as to whether the clothing was weighed before and after 

 the experiment, so the total exhalation of water can not be found. 



Working with the respiration calorimeter of Pashutin, Likhatscheff and 

 Avroroff studied the water vaporized per hour with a young woman who had 

 intermittent malarial fever. 2 The observations reported as " normal " were 

 taken on a day when no fever was present. The subject was 17 years of age 

 and weighed 50 kilos. The water eliminated per hour as water-vapor averaged 

 29 grams during the 22 hours. The lowest output was 24.5 grams per hour 

 between the hours of 5 and 7 a. m., when the subject was asleep and the highest 

 33 grams per hour between 9 and 11 p. m. when awake and reading. 



Using the Jaquet respiration apparatus at Basel with a special attachment 

 for studying directly the water vaporized, Staehelin 3 determined the water 

 vaporized by man in experiments during the night, both after fasting and 

 after various diets. In 5 experiments of 12 hours each the water vaporized in 

 the chamber and passing out in the air-current was 254, 285, 280, 286, and 289 

 grams, respectively. By weighing the bed and bedding he also attempted to 

 obtain the amount of water absorbed by these articles and thus determine the 

 total water vaporized from the body of the man. In the 5 experiments the 

 increase in weight of the bed and bedding, calculated as water, was 78, 101, 

 36, 88, and 201 grams, respectively. Assuming this as water vaporized from 

 the body of the subject but subsequently condensed on the clothing, the total 

 water vaporized from the body in the 5 experiments is 332, 386, 316, 374, and 



1 Lewin, Zeitschr. f. Biol., 1881, 17, p. 75. 



2 Likhatscheff and Avroroff, Reports of the Imperial Military Medical Academy, 

 St. Petersburg, 1902, 5. 



3 Staehelin, Zeitschr. f. klin. Med., 1906, 66, p. 201. 



