J. A. Harris and F. G. Benedict 259 



The purpose of the present paper is threefold: 



1. To obtain some measure of the variability of the basal metab- 

 lism of the normal individual. 



2. To consider the relationship between the length of time over 

 hich the observations extend and the variation in the metabol- 

 im of the individual. 



3. To consider the most suitable method for determining the 

 opulation mean from measurements on a series of individuals. 



II. PRESENTATION OF RESULTS. 



1. Variation of Metabolism in the Individual. 



, For a certain number of men investigated at the Nutrition Lab- 

 I atory the number of days on which measurements were made is 

 itfficiently large (20 or more) to justify the calculation of statis- 

 3al constants for the individual subjects. 



These appear in Tables I to III. 



The constants indicate that individuals are differentiated among 

 lemselves with respect to basal metabolism even when expressed 

 i calories per kilo of body weight or calories per square meter of 

 kly surface area as estimated by the Du Bois height-weight 

 tart. 7 



Furthermore it is clear that the metabolism of each individual 

 sbject is to a considerable degree variable. This is shown by 

 te rather wide range between the maximum and minimum daily 

 Rtabolism for each individual as shown in these tables. These 

 rages are expressed as percentages of the minimum value found 

 i the tables. It is also evident in the absolute variabilities as 



othe minimum value. In another case it varied only 3.5 percent. While 

 i vas pointed out that it was hardly correct to obtain an average value for 

 t; oxygen consumption for individuals with such wide differences in the 

 tie covered by the observations, an average value was determined in the 

 asence of any better available method, and found to be 13.9 per cent. 



7 Since a discussion of the differentiation of individuals with respect to 

 b;al metabolism is not a primary purpose of this paper the subject is not 

 p-sued farther. The statement above may be verified by taking differ- 

 e. es between the various constants and comparing them with their prob- 

 ae errors. It is to be noted that these constants are uncorrected for 

 a&amp;gt;, and that the age differences will, in general, tend to increase slightly 

 tl differentiation of the subjects. 



