268 FOOD INGESTION AND ENERGY TRANSFORMATIONS. 



TABLE 199. A. W. W., April 6, 1907. Sitting. (2-hour periods.) 



Beefsteak: 



Amount, 755 grams; nitrogen, 34.67 grams; total energy, 1,571 cals. 



Fuel value: Total, 1,268 cals.; from protein, 70 p. ct. ; from fat, 30 p. ct. 

 Basal values (March 15 and 21, 1907) : COz, 50 grams; O 2 , 41 grams; heat, 155 cals. 



'Subject ate beefsteak in 54 minutes. 



2 Sample included amount for about 1 hour following the eating of beefsteak. 



food upon the metabolism in the 8 hours of the experimental period, 

 and the experiment is therefore incomplete in this respect. It was of 

 course possible to have made the experiment of 24 hours' duration, 

 subdividing it into three 8-hour periods, but the main purpose of our 

 experimenting was to study the maximum effect in the earlier stages 

 of digestion, and the data are sufficient for this purpose. Thus we 

 find that the maximum increment for carbon-dioxide production was 

 26 per cent, for oxygen consumption 39 per cent, and for heat produc- 

 tion 24 per cent. One anomalous value appears in the results that is, 

 the slightly negative value found for heat production in the first period. 

 This may be taken as essentially the basal value, although undoubtedly 

 an error in direct calorimetry may have accounted for the fact that no 

 increment was noted. The general picture shown in these results is 

 not unlike that of the preceding experiment, namely, a decided increase 

 in all of the factors of the metabolism. The fact that the high incre- 

 ments continued even into the last period indicates that the effect of 

 food ingestion had not begun to decrease at the end of the experiment. 

 A. H. M., May 24, 1907. Approximately half the amount of beef- 

 steak used in the experiment with this subject on April 5, 1907, was 

 taken in the second experiment, the amount in this case being 384 

 grams, with a nitrogen content of 17.63 grams. The basal values 

 used in the first experiment were likewise employed here. The data 

 regarding metabolism, together with those for nitrogen excretion, 

 are given in table 200. An increase in carbon-dioxide production, 

 oxygen consumption, and heat production occurred in the first three 

 periods, with a return to the basal metabolism in the fourth period. 

 We doubtless have here, therefore, the total effect of the ingestion 



