NORMAL PROCESSES OF ENERGY METABOLISM 611 



This table was prepared before it was appreciated bow much tbe 

 metabolism varies witb age and before tbe new method of measuring sur- 

 face area devised by DuBois and DuBois was completed, but it shows how 

 even on the old basis the metabolism was proportional to body surface 

 rather than to weight. DuBois and DuBois in reviewing the literature of 

 surface measurement found that a consistent plus error occurs in the use 

 of the Meeh formula which may rise in very fat individuals to as much 

 as 36 per cent. By their own method (see page 506) checked with actual 

 linear measurements they found a total error in the case of five indi- 

 viduals of widely different shapes of only 1.7 per cent. On the basis of 

 the new method for surface area Gephart and DuBois (b) later gave the av- 

 erage basal metabolism of nine normal men whose surface had been accur- 

 ately measured as 39.7. Cal. per square meter per hour. The extremes of 

 variation in this series were + 4 per cent and 6 per cent. Selecting 

 fat and thin subjects from the work of Benedict, Emmes, Roth and Smith 

 and that of Means the authors find that the fat and thin groups show a dif- 

 ference in metabolism on the basis of weight of 41 per cent while on the 

 basis of "linear formula" (p. 596) for surface area the difference was only 

 3 per cent. The law of surface therefore must be held to apply to fat and 

 thin subjects as well as to the so-called normal. Nevertheless a variation 

 of plus or minus 10 per cent must be expected even in perfectly normal 

 subjects; for there are variations in muscular tonus, in the specific activity 

 of the endocrine organs and in the conducting properties of the skin as well 

 as in other factors not so definitely predictable which must always pre- 

 clude the establishment of a fixed and rigid standard. Means found for 

 example an average for sixteen normal subjects of 38.8 Cal. per sq. M. by 

 the DuBois linear formula and that all came well within the 10 per cent 

 (deviation from average) zone. Harris and Benedict feeling that they 

 had totally discredited the law of surface as a measure of metabolism 

 turned their attention to the prediction of the normal basal metabolism 

 by means of biometric formulas based on stature, body weight, age, and sex 

 and claimed that by this means "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 meas- 



urements." 



Boothby and Sandiford have tabulated 404 determinations of the 

 "basal metabolic rate," as they call it, expressed in percentages above and 

 below normal, using both the standard of DuBois and that of Harris and 

 Benedict. The average rates obtained by the biometric formula of Harris 

 and Benedict are 6.5 points higher than those obtained by the DuBois 

 method. The same authors report that they have made more than 10,000 

 determinations of basal metabolism on healthy people and on patients suf- 

 fering from disease and that "only occasionally have we found patients 



