PREVIOUS STUDIES OF THE METABOLISM OF CHILDREN. 9 



Sonden and Tigerstedt, 1895. Concurrently with the description of 

 the large respiration chamber constructed in Stockholm, Sonden and 

 Tigerstedt reported an extensive series of observations of the resting 

 metabolism of groups of individuals of various ages inside the respira- 

 tion chamber. 1 The prime object of their study was to find the carbon- 

 dioxide output of groups of individuals for use in determining the 

 needs of school-houses and other public buildings for ventilation. 

 Accordingly the investigators attempted to adjust the conditions of 

 their experiments to comply so far as possible with the demands of 

 the rooms and buildings under consideration. The subjects were 

 always in the sitting position, usually after a breakfast, and not 

 infrequently were eating small amounts of candy or apples. The 

 experimental conditions were therefore not ideal for measurements 

 of the basal metabolism. It is no adverse criticism of this wholly 

 remarkable research to state frankly that the results are of no par- 

 ticular value for comparison with later experiments carried out with 

 the primary object of measuring basal metabolism. Notwithstanding 

 this, probably no one research has contributed more to general in- 

 formation as to the caloric requirements of human individuals at 

 different ages than has this study of Sonden and Tigerstedt. The 

 apparatus permitted the determination of the carbon-dioxide con- 

 sumption only, but the investigators were able to compute the energy 

 requirement from this with a considerable degree of accuracy, espe- 

 cially when the food conditions existing prior to and during the experi- 

 ments are considered. 



The experiments were made with subjects varying widely in age, 

 but our own interest in the series at this time centers on the ages prior 

 to puberty. Fortunately their research included an extensive series 

 on children of both sexes, the studies usually being made on groups of 

 six subjects. The boys ranged in age from 7 years and 314 days to 

 14 years and 199 days, and the girls from 7 years and 316 days to 

 14 years and 15 days. All of the children were taken from the schools 

 in Stockholm and remained reasonably quiet during the observations, 

 sitting in chairs and reading. In most of the experiments they ate 

 apples and occasionally candy, but every effort was made by the 

 experimenters to minimize the extraneous muscular activity. The 

 results obtained with both boys and girls are given in table 4, but in 

 considering the data it should be borne in mind that they are not 

 primarily basal values. Sonden and Tigerstedt report their results 

 as carbon dioxide excreted per 6 individuals and per half hour in 

 grams. In presenting the data here we have converted them to 

 calories per kilogram per 24 hours per individual, using the respiratory 

 quotient 0.90 and the calorific value of carbon dioxide for this respira- 

 tory quotient, i. e., 2.785 calories per gram of carbon dioxide. 



1 Sonden and Tigerstedt, Skand. Arch. f. Physiol., 1895, 6, p. 1. 



