194 A BIOMETRIC STUDY OF BASAL METABOLISM IN MAN. 



In male and female infants the deviations of the heat predicted 

 by use of these equations from the actually measured heat-productions 

 are: 



Boy babiet. Girl babies 



Average deviations with regard to sign: 



Prediction from weight -0.020 -0.093 



Prediction from surface +0.118 +0.047 



Average deviations without regard to sign: 



Prediction from weight 11.04 11.16 



Prediction from surface 11.10 11.02 



Square root of mean-square deviations : 



Prediction from weight 13.81 13.77 



Prediction from surface 13.80 13.61 



These results show how slender is the evidence furnished by infants 

 for the assertion that "heat-production is proportional to body-surface 

 and not proportional to body-weight." By the first criterion, surface- 

 area is slightly better in the females but slightly worse in the males. 

 The average deviations without regard to sign show that in the females 

 prediction from body-surface there is an average error of 0.14 calorie 

 per day less than in prediction from body-weight, but that in the males 

 prediction from body-surface area by the Lissauer formula gives 0.06 

 calorie worse prediction ! Relying upon the square root of mean-square 

 deviation for the most critical test, we note that there is a difference 

 between the two methods of only 0.01 and 0.16 calorie per day! The 

 differences are trivial in comparison with the average daily metabolism 

 of over 140 calories for infants of both sexes. In short, body-weight 

 and body-surface area are equally good for purposes of prediction. 



Turning now to the prediction of total heat-production from mul- 

 tiple regression equations based on the whole series, we have the 

 equations, 



For boy babies h= -22.104+31.050 w + 1. 162s 



For girl babies h = -44.901 +27.836 w + 1.842 s 



The theoretical heat-production for each infant has been cal- 

 culated by these formulas and compared with the actually observed 

 heat-production. 



The theoretical average deviation with regard to sign is zero and 

 is actually 0.078 calorie per day in the males and 0.047 calorie 

 per day in the females. The average deviation without regard to sign 

 is 11.02 calories in the males and 10.84 calories per 24 hours in the 

 females. Measuring the suitability of the formulas by the square root 

 of mean-square deviations we find 13.78 calories for the males and 

 13.53 calories for the females. 



Comparing these results with those secured by prediction from 

 body-weight and body-surface above, we note that prediction from 

 stature and body-weight simultaneously has given slightly better results 

 than prediction from either body-weight or body-surface alone. 



