138 Metabolism of Healthy Man. 



a temperature of 20 C. and a relative humidity of 40 per cent, there were on 

 the average 91 grams of water vaporized per hour. With a relative humidity 

 of 65 per cent, 1 experiment showed that 31.6 grams of water were vaporized 

 per hour. 



In a general summary of this topic, Eubner 1 has collected some of the data 

 obtained by his associates. On 1 person, F., with a body-weight of 71 kilos, 

 at a temperature of 14 C, there were 45 grams of water vaporized per hour; 

 at 17.4 C, 29.6 grams; and at 23.5 C, 54.4 grams. 2 Another subject, H., 

 weighing 58 kilos, well nourished, showed in a series of experiments with 

 widely varying relative humidity, at 15 C, 36.3 grams per hour in dry air 

 (8 per cent humidity) and 9 grams per hour in moist air (84 per cent humid- 

 ity) ; at 20 C, the quantities were 54.1 and 15.3 grams, respectively, and at 

 23 C. they were 72.8 and 18.7 grams, respectively. 3 



One of Eubner's associates, Wolpert, made a large number of experiments 

 with the subject, Br., whose body-weight was 58 kilos. In the winter time, 

 with summer clothing, he gave off, at 15 to 20 C. temperature, 19 grams of 

 water-vapor per hour, an unusually low amount. 



In connection with an extended series of experiments with a large respira- 

 tion chamber in Stockholm, Sonden and Tigerstedt 4 determined the water 

 vaporized for a number of individuals. The accuracy of their determinations 

 of water has been called into question by the authors themselves and leaves 

 considerable to be desired. Nevertheless, the results have an interest. Of the 

 experiments with the large number of different individuals studied, those most 

 comparable with the experiments here reported are with a group of men 19.5 

 to 23 years of age with which there were 2 experiments (6 subjects in each 

 experiment), where the water-vapor per hour was found to be 46 grams. 



EXPERIMENTS ON THE WATER VAPORIZED FROM LUNGS AND SKIN. 

 Method Used and Accuracy of Determinations. 



In the respiration calorimeter at Wesleyan University direct determinations 

 of the water vaporized from the body were made in practically all experiments, 

 and they furnish by far the most satisfactory data for deducing the normal 

 water-vapor output of resting man living under the conditions obtaining inside 

 the respiration chamber, and furnish evidence for a discussion of the significance 

 of the water-vapor elimination, its fluctuations and the factors that affect it. 

 In nearly all of the experiments recorded herewith, and in the large majority 

 of those made previously with the same apparatus and recorded in other publi- 

 cations, the water vaporized was determined with considerable accuracy. This 

 is particularly true in rest experiments. The method of bringing away the 



1 Rubner, Die Gesetze ties Energleverbauchs bei tier Ernahrung, Leipsic and 

 Vienna, 1902, p. 203 et seq. 



2 Rubner, Archiv f. Hygiene, 1900, 38, p. 133. 



3 Rubner and v. Lewaschew, Archiv f. Hygiene, 1897, 29, p. 33. 



4 Sonden and Tigerstedt, Skand. Archiv f. Physiol., 1895, 6, p. 99. 



