A CRITIQUE OF THE BODY-SURFACE LAW. 193 



totals) the differences range from 6.3 to 134.0 calories, or from 0.38 

 to 10.01 per cent of the average (24-hour) heat-production of the group 

 of subjects under consideration. 



If one prefers to base his judgment concerning the value of the 

 different means of estimating the basal metabolism of an unknown 

 subject upon the square root of the mean-square deviation of the 

 computed from the actually observed values, he may examine the 

 results set forth in table 75. Here again the 45 tests of the suitability 

 of the multiple regression equation involving stature, weight, and age 

 with two trivial exceptions (+2.6 calories = 0.16 per cent and +3.1 

 calories = 0.19 per cent) indicate the superiority of these equations 

 over the 5 other methods which have been tested. The values for the 

 larger series (IV-VII and totals) range from 0.73 to 14.30 per cent. 



Considered in their relation to the problem of the present chapter, 

 that of the body-surface law, the tables of this and the preceding 

 section show that results as good as or better than those obtainable from 

 the constant of basal metabolism per square meter of body-surface can be 

 obtained by biometric formulas involving no assumption concerning the 

 derivation of surface-area but based on direct physical measurements. 



To the practical application of these formulas we shall return in 

 the two following chapters. 



11. COMPARISON OF BODY-WEIGHT AND BODY-SURFACE AS BASES OF 

 PREDICTION IN MALE AND FEMALE INFANTS. 



Unfortunately our series of new-born infants are not large enough 

 to justify division into subseries for the purpose of testing the suita- 

 bility of different methods of prediction by the treatment of the indi- 

 viduals of one subseries as unknown. We must, therefore, test the 

 value of the different methods of predicting the total heat-production 

 of an infant by comparing the actually measured heat-production with 

 that computed from constants based on the series to which it belongs. 83 



It seems worth while to test only the methods of predicting total 

 heat-production from body-weight and from body-surface by the linear 

 regression equations, and by multiple-regression equations based on 

 both weight and stature. 



The linear equations required are : 



For male babies: For female babies: 



h= 25.156-f 34.517 w h= 26.184+ 34.229 w 



h = -31.703+749.914 a, T . h= -32.048+751.548 a L 



83 Unfortunately the Du Boises have not as yet prepared a height-weight chart for infants 

 and we are in consequence limited to the Lissauer formula, which may in time be discarded like 

 the Meeh formula for adults. An extensive series of measurements made in conjunction with 

 Dr. Fritz B. Talbot and according to the Du Bois plan of measurement has shown quite re- 

 markable agreement between the surface areas of infants computed (l) by the Lissauer formula 

 (2) by the Du Bois linear formula, t. e., so far as normal infants weighing up to approximately 

 10 kilograms are concerned. For infants weighing more than 10 kilograms the Lissauer for- 

 mula gives results unquestionably too small. Measurements are now being collected for under- 

 nourished and atrophic infants. 



