PREVIOUS STUDIES OF THE METABOLISM OF CHILDREN. 7 



made by the Pettenkofer and Voit method, and include observations 

 on older children, it seems advisable to consider them somewhat more 

 extensively here. In his recognition of the importance of a study of 

 the metabolism of youth, Forster was undoubtedly stimulated by the 

 wonderful observations of Pettenkofer and Voit. The statement made 

 in our earlier publication, 1 that he used the large Pettenkofer- Voit 

 respiration chamber, is obviously erroneous; we have been unable to 

 find a description of the exact size of chamber that he used. In 

 amplification of the records of Forster's investigations previously 

 reported by us, the following data should be given: 



Forster 2 states that he studied a number of children varying in age 

 from 14 days to 13 years, using a Pettenkofer- Voit respiration chamber 

 and determining the carbon-dioxide excretion. The experiments 

 with nursing infants, which continued from 3 to 5 hours each, were 

 made in the intervals between the nursings. With the other children 

 the experiments were made in the morning. The supper given the 

 children the night before the experiment consisted of milk with a little 

 bread; from If to 2 hours before the beginning of the experiment, 

 they all received 100 grams of milk and a small piece of bread (about 

 50 grams). During the experiments the nursing infants slept the 

 greater part of the time; the other children remained very quiet, for 

 the most of the time sitting and with nothing special to do. In con- 

 formity with the usage of a number of writers at about that period, 

 Forster reported his results as grams of carbon-dioxide excreted per 

 hour for each 10 kg. of body-weight. The results are given in table 3. 



TABLE 3. Carbon-dioxide production of children (Forster) 



These values, which are not far from 10 to 12 grams per hour for each 

 10 kg. of body-weight, Forster compares with those obtained by 

 Pettenkofer and Voit for men calculated to the same basis of body- 

 weight. The values for adults are, for the most part, one-half of 

 those found with the children. Forster concluded that, since the 

 children during the experiment were usually quiet and with approxi- 

 mate hunger, there is a very much greater oxidation of nitrogen-free 

 material with children than with adults under the same external 



1 Benedict and Talbot, Carnegie Inst. Wash. Pub. No. 201, 1914, p. 11. 



2 Forster, v. Ziemssen's Handbuch der Hygiene, Leipsic, 1882, 1, p. 76. 





