14 Metabolism of Healthy Max. 



by a number of short experiments made on him in different physiological 

 laboratories, but while numerous observations regarding bis body-weight and 

 strength had been made, as well as urine and fecal analyses, there had been 

 no opportunity to study his gaseous exchange. Xeither his total metabolism 

 nor his carbon-dioxide production had previously been studied, and hence there 

 was no evidence regarding his total requirements for energy. It seemed 

 especially interesting, therefore, to make a study of this subject and find what 

 were his energy requirements as compared with other individuals of like body- 

 weight and activity. 



The calorimetric features of this apparatus had unfortunately been seriously 

 disturbed in the process of alteration from an open-circuit respiration appa- 

 ratus of the Pettenkofer type to a closed-circuit apparatus of the Eegnault- 

 Reiset 1 type and hence we were unable to secure satisfactory heat measure- 

 ments during this experiment. However, the general widespread interest in 

 the metabolism of this subject warrants our reporting the results for the nitro- 

 gen and carbon balance. A subsequent experiment with this subject, in which 

 the carbon-dioxide and water-vapor elimination, oxygen consumption, and heat 

 production were simultaneously determined, has been published in detail 

 elsewhere. 2 



The subject entered the respiration chamber in the evening of March 23, 

 1903, and regular observations began at 1 a. m., March 24. Five 6-hour 

 periods were obtained with this man, the experiment ending at 7 a. m., March 

 25. The diet for several days before had not been unlike that taken during 

 the experiment, judging by the general impression of the subject, although he 

 was not under observation at that time. The analyses of the urine had sub- 

 stantiated this view, at least so far as the nitrogenous ingredients of the diet 

 were concerned. The usual separations of the urine in different periods of the 

 day, four 6-hour periods, were made. It was not considered practicable, how- 

 ever, to attempt to separate the feces as the experiment was so short. 



Program and record of activity. The subject was accustomed to keeping 

 very irregular hours, retiring early and frequently rising in the middle of the 

 night, in fact, following no definite program. Hence, while all previous experi- 

 ments had been made with a regular program, it was here considered advisable 

 to allow this subject to follow his own inclinations with regard to sleeping 

 and moving about, the only stipulation being that he should consume his food 

 between 7 a. m. and lip. m. 



The amount of muscular activity indulged in by this subject was not re- 

 corded with as much detail as in the subsequent experiment, and therefore a 

 complete interpretation of the metabolism from period to period is not possible. 

 The records as made by the different observers have been compiled and are 

 given herewith. 



1 Regnault and Reiset, Ann. de Chim. et de Phys., 1849, ser. 3, 26. 

 'Benedict and Milner, U. S. Dept. Agr., Office Exp. Stas. Bui. 175, 1907, p. 84. 



