FOODS — NUTRITION". 



973 



urements of energy. The following table shows the average percentages of energy 

 given off from the body in the rest and work experiments: 



Percentages of total fnenju yiven off from the body in different ways. 



Heat. 



In rest 

 experi- 

 ments. 



In work 

 experi- 

 ments. 



From skin bj- radiation and conduction (and in exhaled air) 



In urine and feces 



In water vaporized from lungs and skin 



Heat equivalent of external muscular work done 



Per cent. 



74.2 



1.4 



24.4 



Per cent. 



62.3 



.5 



30.8 



6.4 



Total. 



100.0 



The following table compares the amounts of potential energy in the food materials 

 actually oxidized in the body with the amounts of kinetic energy given off from the 

 body, either as heat alone in the rest experiments, or as heat and external muscular 

 work in the work experiments: 



Comparison of income and outgo of energy in 19 e.vperipients covering 65 experimental 



days — Amounts per day. 



Subjects and kinds of experiments. 



Num- 

 ber of 

 experi- 

 mental 

 days. 



Net income xt„(. „„to.„ 

 (potential l(^f*°k-ln ' 

 energy of i^r. ".. ' ivoV, Difference (in terms 



material 

 oxidized 

 in body). 



ergy gn 

 off from 

 body. ) 



of net income). 



REST EXPERIMENTS. 



Experiments with E. O.: 



Experiment in which the net outgo falls 

 farthest below the net income (No. 5); 



average for the whole experiment 



Experiment in which the net outgo is far- 

 thest above the net income (No. 14); aver- 

 age for the whole experiment 



Average for 9 experiments 



Experiments with A. W.S.: Average for 1 experi- 

 ment , 



E.xperiments with J. F. S.: Average for 3 experi- 

 ments 



Experiments with E. O., .\. W. S., and J. F. S.: 

 Average for 13 experiments 



WORK EXPERIMENTS. 



Experiments with E. O.: Average for 2 experi- 

 ments 



Experiments with J. F. S.: Average for 4 experi- 

 ments 



Experiments with E. O. and ,1. F. S.: Average for 



6 experiments 



Re.st and work experiments: Average for 

 19 experiments 



Calories. 

 2,482 



2,131 

 2, 288 



2, 304 



2,118 



2,2.55 



3,865 

 3,539 

 3,669 

 2, 690 



Calorie.^. Calories. 

 2, 379 -103 



2,193 



2, 278 



2,279 

 2, rS6 

 2, 2.50 



+ 62 

 - 10 



- 25 



+ 18 



3,829 - 36 



3,540 I -f 1 

 3,656 i - 13 



Per cent. 

 -4.1 



-1-2.9 



- .4 



-1.1 

 + .8 



- .2 



- .9 







- .4 



- .3 



The authors note that the experiments reported practically afford a demonstration 

 of the action of the law of the conservation of energy in the living organism. 



Results of experiments on the metabolism of matter and energy in the 

 human body, W. 0. Atw.vtki;, F. G. Benedict, et al {Connecticut Starrs Sta. Rpl. 

 1900, ]>p. 0(!-Uf>). — Noted above from another publication. 



Contribution to the subject of metabolism of matter and energy in man, 

 A. Loewv and F. ^Iullek {Arch. Anal. u. I'liysioL, Physiol. Alt., 1901, pp. 299-322; 

 abs. in Ztscltr. Vntersucli. Nahr. n. (h'nussmtl., 5 {1902), Xo. 6, p. 262). — Experiments are 

 reported of which one of the authors was the sul)ject. During 4 days only ordinary 

 laboratory work was performeil. During the 6 remaining days of the experimental 



