20 METABOLISM AND GROWTH FROM BIRTH TO PUBERTY. 



12 per cent; Reg. F., 15 per cent; Harry B., 4 per cent; Raymond M., 

 7 per cent; Henry K., 13 per cent; and Leslie B., 25 per cent. Thus 

 out of the eight boys whose values were used for basal averages, four 

 show a difference of 12 or more per cent between the results obtained 

 in the two periods. When there is a difference of but 3 or 4 per cent, 

 an average may legitimately be used, but with variations so large as 

 these, it is clear that one of the two periods may approach the basal 

 metabolism and the other must be above it. Under these conditions 

 the averaging of the values is questionable and tends to give a high 

 value for the basal metabolism. Du Bois concludes that these boys 

 show on the average a heat production per unit of surface area accord- 

 ing to the Du Bois linear formula which is 25 per cent higher than 

 the level for adults. In analyzing the figures, however, the wide 

 variations between the results of the two periods should be borne 

 in mind, for values differing 12 per cent or more can hardly give a 

 satisfactory base-line. If the lower of the two values is selected to 

 represent the base-line, this would reduce very perceptibly the average 

 increase above the adult level. It may be questioned, therefore, 

 whether even the lowest value represents the basal metabolism, and a 

 second experiment on each boy to control these important findings 

 would have been of inestimable value. 



Olmstead, Barr, and Du Bois, 1918. Recognizing the importance 

 of studying the metabolism of young boys at about the age of puberty, 

 Du Bois and his associates 1 repeated the series of experiments which 

 were made with boys in 1916 to study the changes in the metabolism 

 after two years of growth. In this series the wide variations between 

 the two periods were eliminated, the only two subjects showing differ- 

 ences of 12 per cent or more being J.D.D.B. and Reg. F. The former 

 was not included in the calculation of the basal metabolism; the latter 

 showed a variation of 17 per cent. Since the experimental conditions 

 apparently approached the normal, it is probably legitimate in all cases 

 except Reg. F. to average the results of the two periods, although it 

 is still open to question whether duplicate experiments on separate 

 days should not have been made. 



The authors note a pronounced decrease in metabolism in this second 

 series of experiments as compared with the results of the first series, 

 the boys when two years older showing a decrease in the metabolism of 



13 per cent. If the minimum values obtained in the first series of 

 experiments were used for the basal metabolism instead of the average 

 of the two periods, this decrease would obviously be less. All the 

 evidence seems to imply that the conditions under which the first 

 experiments were made were abnormal in that the subjects had a 

 much more irregular metabolism than would normally be expected. 



1 Olmstead, Barr and Du Bois, Arch. Internal Med., 1918, 21, p. 621. 



