PREVIOUS STUDIES OF THE METABOLISM OF CHILDREN. 23 



obtained with the subject during sleep, his experiments would have 

 contributed towards our knowledge of the basal metabolism. Magnus- 

 Levy and Falk's results approach more nearly the modern idea of 

 basal metabolism, for these experimenters insisted upon repose and 

 upon absence of food. 



While it is assumed by Sonden and Tigerstedt and by other workers 

 that the same degree of muscular activity can be approximated with 

 children of different ages when complete muscular repose is not 

 insisted upon, this still remains to be proved and may fairly be ques- 

 tioned at this tune. It is quite possible that the relatively great 

 differences in the activity of children, youths, and adults may account 

 for the peculiar findings recorded by these several schools when an 

 attempt is made to superimpose a definite amount of activity upon 

 the modern standard of complete repose. 



From a purely scientific standpoint, clear-cut conditions are essential 

 for comparative experiments, and if one wishes to study the differences 

 in metabolism due to differences in age or sex, and particularly for 

 the various diseases, we must have uniform conditions. The basal 

 condition presents especially good opportunities for such uniformity. 

 Studies of this kind are particularly advantageous in clinical calor- 

 imetry, for most of the subjects observed would be bed-ridden or 

 hospital patients, spending a considerable part of their time under 

 conditions of muscular repose. 



The experiments of Sonden and Tigerstedt served their special 

 immediate purpose perfectly, namely, to supply knowledge regarding 

 the carbon-dioxide production in school rooms and halls of a group 

 of young children. Rubner's experiments on two boys served his 

 special purpose, but neither series can be considered as more than 

 studies of metabolism under special conditions. This likewise applies 

 to the major part of the respiration calorimeter experiments made 

 at Wesleyan University. Each series demonstrated its special highly 

 important and fundamental point, but few of the experiments are 

 useful for further comparison. The night experiments at Wesleyan 

 University began at 1 a. m. and were ended at 7 a. m., while the subjects 

 were still in bed, so that results were obtained almost invariably for 

 six hours of repose. They are therefore of more general use, since the 

 subject was asleep and quiet, with the influence of food at a minimum. 



It is the duty of twentieth-century experimenters to make experi- 

 ments of more than passing value. Each experiment should contribute 

 to our fundamental basal knowledge. Each year sees an increase in 

 the significance of normal values; an effort should therefore be made 

 to secure normal values which will be of service not simply in the 

 current year but for a decade. There is no excuse for present-day 

 controls which do not meet modern requirements. Hundreds of 

 experiments with men and women in this laboratory have shown that 



