240 Metabolism of Healthy Max. 



erroneous to draw deductions from experiments on only 2 individuals, but we 

 are inclined to think that the difference in chemical composition of the body as 

 a whole, and the larger proportion of fatty tissue would account for the lower 

 metabolism that women exhibit as compared with men. 



In previous discussions in this section but little attention has been given to 

 the water of vaporization. In this one regard there seems to be an especially 

 noticeable difference between the metabolism of women and men. A compari- 

 son of the values given in table 100 for the 2 women with the results on 55 men 

 at rest shows that the 2 women excreted per kilogram of body-weight per hour 

 considerably more water-vapor than did all but 1 of the 55 men. A recent 

 (November, 1909) experiment with a woman in the Nutrition Laboratory 

 showed, also, a very much larger water vaporization per hour than with men 

 subjects, thus further confirming the observations reported on the subjects, 

 C. F. S. and G. E. B. 



The previous experimental evidence with regard to the water-vapor excretion 

 of women as compared with men is unfortunately very limited. In the experi- 

 ments of Sonden and Tigerstedt the determinations of water-vapor were not 

 made in all experiments with men and with women, but the authors, point out 

 that the relation of carbon dioxide to water-vapor with men is not far from 

 100 : 106, while with women the relation is as 100 : 131. Clearly, then, this 

 relation of itself does not indicate anything definite with regard to the point 

 under discussion, namely, the absolute output of women as compared with men, 

 for the relationship may be larger with women than with men in that the 

 carbon-dioxide excretion was smaller rather than the water vaporization larger. 



In this connection it is somewhat interesting to consider the results, obtained 

 with a fat man by Schattenfroh * in Buhner's laboratory. As a result of his 

 experiments, Schattenfroh concluded that fat people exhale considerably more 

 water-vapor per square meter of body-surface than do lean people. If this is 

 the case, then, we have a natural explanation of the apparently higher water 

 vaporization of women than of men, inasmuch as there is admittedly a much 

 larger proportion of subcutaneous fat per kilogram of body-weight with women 

 than with men, and consequently the body of a woman would approximate in 

 chemical composition that of a fat man. 



It is obvious that the results are sufficiently characteristic to justify further 

 experiments. The actual determined differences in the metabolism of men and 

 women are too few and hence this apparently sharply defined point should be 

 thoroughly substantiated by a large number of experiments. 



1 Schattenfroh, Archiv f. Hygiene, 1900, 38, p. 93. 



