Metabolism Experiment No. 102. 23 



Comparison with results in similar experiments. The 3-day experiment, 

 made subsequent to this and published elsewhere, is much more detailed, and it 

 is of interest to compare these days with the experiment in hand. In this com- 

 parison it is necessary to note that on the 3 days of the experiment already 

 published the bodily activity did not exceed, if indeed it was not considerably 

 less than, the bodily activity during this experiment. While the impression 

 of the subject that he had worked on the typewriter for 12 hours is unques- 

 tionably too large, and the work on the typewriter was more or less desultory 

 in nature, it is probably fair to assume that the work thus done was not more 

 than the equivalent of 4 or 5 hours' continuous typewriting by a person accus- 

 tomed to the use of the machine. Experiments made subsequent to this experi- 

 ment have shown that the amount of energy above the resting metabolism 

 required to write 1600 words per hour on the typewriter is not far from 25 

 calories, and hence we may assume that the work of typewriting in this case 

 involved an expenditure above the resting metabolism of not much more than 

 25 calories per hour. 1 



Accuracy of indirect method. For purposes of accurate comparison of the 

 two experiments with this subject, the only index of which we can be perfectly 

 sure is the carbon elimination. This is a reasonably accurate index of the metab- 

 olism of this subject, inasmuch as during this experiment he was using a diet 

 somewhat deficient in energy but containing a large proportion of carbohydrate, 

 and hence the dietetic conditions in the two experiments did not differ widely. 

 While, therefore, the actual heat production by direct calorimetry is missing 

 in this experiment, the heat production by indirect calorimetry is known with 

 reasonable accuracy, and although frequently there are wide discrepancies be- 

 tween the direct and indirect calorimetry when comparisons are made in short 

 periods, the values for 24-hour periods agree very satisfactorily. This is true 

 even under such adverse conditions for experimenting as those obtaining during 

 fasting, where the difference in the nature of the composition of the body sub- 

 stance at the beginning and end of the experiment is much greater than is the 

 case when the diet on the day preceding is essentially that of the experiment 

 and when at 7 o'clock each morning the body may be said to be in the same 

 equilibrium with regard to material. 2 



METABOLISM EXPERIMENT No. 102. 



Subject, W. O. A., April 17-18, 1903. Age, 59 years; height, 

 168 cm.; weight without clothing, 84.8 kilos. 



From these data it is seen that the subject was distinctly fat. He entered 

 the respiration chamber on the evening of April 16, 1903, went to bed at the 

 usual time, and rested comfortably until morning. He reported that during 

 the night he slept fairly well, but not so soundly as usual. He woke several 



1 Carpenter and Benedict, Journ. Biol. Chem., 1909, 6, p. 271. 



2 Benedict, Carnegie Institution of Washington Publication No. 77, p. 85, 1907. 



