INTRODUCTORY. 7 



been considered in detail. Standard tables have been prepared from 

 which the most probable metabolism of a subject, whose normal metab- 

 olism is unknown, may be predicted as a basis of comparison with that 

 measured in a pathological state. Such tables should be of great value 

 in the clinical investigations which should contribute much to the 

 future advancement of medical science. 



6. By the use of such tables, the metabolism of subjects of par- 

 ticular characteristics, or subjected to special conditions, has been 

 reconsidered. Specifically, the problems of the typical or atypical 

 character of certain series of metabolism measurements, of the differen- 

 tiation of the sexes with respect to metabolic activity, of the metabolism 

 of athletes as compared with non-athletic individuals, of vegetarians 

 as compared with non-vegetarians, and of individuals suffering from 

 disease have been investigated. 



In preparing this report on the results of the application of the 

 biometric formulas to the data of basal metabolism in normal men and 

 women we have utilized only the measurements made at the Nutrition 

 Laboratory or by those who have been associated with it. This limita- 

 tion has been made, not because there are not many satisfactory deter- 

 minations which have been made in other laboratories, but because, 

 all things considered, it has seemed most satisfactory to avoid invidious 

 comparisons by the discrimination which would have been necessary 

 had we gone outside the series of determinations for which responsibility 

 rests directly or indirectly upon the Nutrition Laboratory. 



Finally, a few words concerning the form in which the results of 

 this investigation are presented : It has not seemed desirable to trans- 

 form a research publication into a primer of statistics, or to state results 

 which are necessarily mathematical in a popular and non-mathematical 

 form. We have, however, made every effort to express our results in 

 a form so clear and direct that they will be fully comprehensible to 

 those without special statistical training. In the case of all the more 

 complicated processes we have given the formulas by which the results 

 were reached. This has been done to enable those who may care to do 

 so to check through our work from the beginning. The reader who is 

 interested in end results rather than in methods should pass over these 

 features, just as the general biologist must pass over the details of 

 method and the section on structural formulas in a paper by an organic 

 chemist, realizing that they are essential to the technical development 

 of the subject. The analogy is by no means wide of the mark. The 

 statistical technique is of course complicated, as are the manifold 

 technical refinements necessary in the experimental phases of the 

 measurement of metabolism in man. An adequate presentation of the 

 subject demands a statement of the formulas employed quite as much 

 as a description of the physical and chemical apparatus used in the 

 laboratory phases of the work. With this feature of the following 



