16 METABOLISM AND GROWTH FROM BIRTH TO PUBERTY. 



in computing the values for asleep the author did not select absolute 

 minimum values, but rather took an average representing the entire 

 time the subject was in bed. Thus he disregards completely the 

 wholly impossible variations in the carbon-dioxide production from 

 period to period. 



TABLE 8. Comparison of carbon-dioxide production of boys awake and asleep (von Willebrand). 



This whole research is very perplexing. The differences in the 

 carbon dioxide found in the 2-hour periods in different experiments 

 with the same individual, presumably when he is asleep, are extra- 

 ordinary. Such differences are wholly outside of our experience in 

 the Nutrition Laboratory or at Wesleyan University. It appears as 

 though there must be a gross experimental error, and yet Tigerstedt 

 proves that the carbon-dioxide determinations in this apparatus 

 ought to be accurate to within 0.76 gram carbon dioxide. 1 If an 

 attempt were made to use the absolute minimum figures, one would 

 find values for the carbon-dioxide production per 2 hours on the 

 experimental days with Veikko of 11.9, 10.1, 22.2, and 18.5 grams; 

 with Viktor, 33.8, 15.2, 34.5, and 17.0 grams; with Julius, 15.1, 33.6, 

 and 21.5 grams; and with Silo, 21.9, 25.9, and 18.9 grams. These 

 low values were not confined to any one part of the day, but varied 

 widely as to the time they appeared. 



Niemann, 1911. Laying special emphasis upon the 24-hour metab- 

 olism of a bottle-fed baby, and employing the small Pettenkofer- 

 Voit chamber, Niemann, 2 in Heubner's clinic, studied a male child 

 designated as " normal," but with a body- weight somewhat low for the 

 age. The child was studied at the age of 3f months for 7 days, 

 again at 5 months for 6 days, at 8 months for 6 days, and at 9 months 

 for 17 days. Since the metabolism measurements were made for the 

 entire 24 hours, and no subdivision can be made for the periods when 

 asleep, values for basal metabolism are not obtainable. As an index 

 of the total 24-hour caloric output of children, however, this experi- 

 ment, along with others of the Heubner clinic and from the Kaiserin 



1 Tigerstedt, Skand. Arch. f. Physiol., 1906, 18, p. 304. 



2 Niemann, Jahrb. f. Kinderheilk., 1911, 74, pp. 22, 237, and 650. 



