200 A BIOMETRIC STUDY OF BASAL METABOLISM IN MAN. 



proper, however, to point out that since the long existing doubts as 

 to the validity of the older methods for the measurement of body- 

 surface have been fully substantiated by the development of the linear 

 formula of the Du Boises for adults and the photographic method, it 

 is quite possible that more intensive work will draw into question the 

 validity of the surface measurements upon which the evidence of the 

 applicability of the law to animals in general depends. If the errors 

 in the Meeh formula are as large as those pointed out by the Du Boises, 

 one may also reasonably question the formulas for lower animals. It 

 is thus probable that the computations of E. Voit, recently approved 

 by Armsby, will need a radical revision. What influence this revision 

 may have upon the general acceptance of the wider applicability of the 

 so-called body-surface law awaits determination. 



Finally, in view of the facts that (a) the equations developed in 

 this volume and the convenient tables 9l which have been provided for 

 the prediction of the basal metabolism of the individual from stat- 

 ure, weight, and age deprive the "body-surface law" of its unique 

 practical significance, and that (6) the evidence of an actual physio- 

 logical nexus between body-surface area and metabolism is altogether 

 inconclusive, it seems to us that the "body-surface law," as far as its 

 supposed application to the human individual is concerned, must play 

 a very minor role indeed in future physiological discussions. 



The equations which we have given were designed primarily for 

 the most exact work in the problem of metabolism during the period of 

 adult human life. While for this period they are decidedly superior 

 to prediction by means of the average heat production per unit of body 

 surface in a standard series we would not at present recommend the 

 discarding of the older methods of correcting for body size in compara- 

 tive studies of metabolism. 



Body-weight, the two-thirds power of body-weight, and the more 

 recent attempts at actual surface measurement must be considered 

 in comparing organisms of very different phj^sical configuration. 

 We must, however, point out that our experience with the "body- 

 surface law" in its application to the human individual indicates that 

 extraordinary caution must be used in regard to all of these methods. 

 Eventually they will probably have to be replaced by standards similar 

 to those developed for human adults in this volume. 



Until this can be done on the basis of adequate physical and experi- 

 mental data we do not desire to have our results for adults generalized 

 beyond the range of physical characters and age to which we have 

 ourselves applied them. If this were done they might tend to hinder 

 rather than to assist in the advancement of research. For the present 

 at least, the older methods of comparison must still be appealed to 

 in the inter-specific comparisons. 



91 See Chapter VIII for a full discussion of theee tables. 



