272 



FOOD INGESTION AND ENERGY TRANSFORMATIONS. 



F. M. M., December 10, 1908. A somewhat smaller amount of beef- 

 steak was taken by this subject than that taken by the subject of the 

 preceding experiment, the amount in this case being 217 grams, with a 

 nitrogen content of 9.97 grams. As in the experiment with J. R., 

 the urine was collected every 2 hours. The results of the experiments 

 are given in table 203, from which it is seen that the increase in carbon- 

 dioxide production in each of the first three periods amounted to 

 3 grams or over; in the 5 hours following it was practically 1 gram 

 above the basal value. Since a possible error of 1 or 1.5 grams in the 

 basal value is permissible, one may conclude from the values for carbon- 

 dioxide production alone that the basal value was reached at the end of 

 the third hour. Irregular increments, which are difficult to explain, 

 were found for oxygen consumption throughout the whole experiment. 

 The maximum increase was 7 grams in the first hour and the lowest, 

 0.5 gram, in the fifth period. Somewhat large increments were noted 

 in the sixth, seventh, and eighth hours which indicate that if the experi- 

 mental technique were accurate, the basal level was not reached at 

 the end of the experiment. A measurable increment in heat produc- 

 tion occurred in the first 3 hours, but subsequently irregular values 

 were found, with an increase of 5 calories in the sixth period, followed 

 by a decrease of 6 calories in the seventh period, this variation possibly 

 indicating a compensation. From the standpoint of direct calo- 

 rimetry, the experiment can hardly be called successful. If we base our 

 conclusion upon the values obtained for carbon-dioxide excretion and 

 heat production, it is probable that the basal level was reached in 

 approximately the fourth hour. The respiratory quotients indicate a 

 leakage of air in the last three periods. 



TABLE 203.^. M. M., December 10, 190S. Sitting. (1-hour periods.) 

 Beefsteak: 



Amount, 217 grams; nitrogen, 9.97 grams; total energy, 451 cals. 



Fuel value: Total, 364 cals.; from protein, 70 p. ct.; from fat, 30 p. ct. 

 Basal values (December 9, 1908) : CO2, 25 grams; Oa, 21 grams; heat, 77 cals. 



'Heat eliminated corrected for change in body-weight, but not for change in body-temperature. 



