206 



Metabolism of Healthy Man. 



water- vapor output are the series made by Pettenkofer and Voit * with the large 

 respiration chamber at Munich. These experimenters determined the water 

 vaporized, as well as the carbon dioxide exhaled, but more stress was laid upon 

 the determination of carbon dioxide, and they recognized the possibility, indeed 

 the probability, of a rather considerable error in the determination of water. 

 However, the results as presented by them make possible certain calculations 

 with regard to the ratio of carbon dioxide to water-vapor. In table 85 these 

 ratios have been computed for the rest experiments. Considering the carbon 

 dioxide as 100, the values in the table indicate the ratio for water. 



Table 85. Ratio between carbon dioxide eliminated and water vaporized in 

 experiments reported by Pettenkofer and Voit. 



[Carbon dioxide taken as 100.] 



Lewin 2 in 1881, making a series of experiments in the Pettenkofer respira- 

 tion apparatus, determined both the carbon dioxide exhaled and water vapor- 

 ized and the ratios found in 5 experiments during the night were as follows : 

 100 : 88, 120, 112, 112, and 116, respectively. 



Using the Pashutin respiration apparatus, Sadovyen 3 in 1888 made a series 

 of experiments in which both the carbon-dioxide elimination and water vapor- 

 ized were determined. 



In 3 experiments with a mixed diet the ratios were 100: 178, 115, and 170, 

 respectively. During a 2-day fast, 127 and 111 were found. In a 4-day fast, 

 the ratios were 90, 89, 96, and 116, while with a non-nitrogenous diet containing 

 only carbohydrates for 3 days the ratios were 163, 107, and 104. All the experi- 

 ments were made with the same subject. 



In their research on the total metabolism of different individuals, Sonden 

 and Tigerstedt 4 determined the water-vapor in a number of experiments and 

 they have computed the carbon-dioxide and water-vapor ratio for several of 

 their subjects. The results are abbreviated in table 86. 



Using the Pashutin respiration apparatus, Likhatscheff B reports 6 experi- 

 ments with healthy subjects in which both the carbon-dioxide elimination and 

 water vaporized were computed. The 24-hour ratios are as follows: 4 experi- 



1 Pettenkofer and Voit, Zeitschr. f. Biol., 1866, 2, p. 459. 



2 Lewin, Zeitsichr. f. Biol., 1881, 17, p. 71. 



3 Sadovyen, loc. cit. 



4 Sonden and Tigerstedt, Skand. Archiv f. Physiol., 1895, 6, p. 97. 



5 Likhatscheff, loc. cit. 



