276 



FOOD INGESTION AND ENERGY TRANSFORMATIONS. 



period, the nitrogen excretion being 0.52 gram per hour. The incre- 

 ment in carbon-dioxide production in the first 4 hours of this 5-hour 

 experiment was considerable. Both the oxygen consumption and heat 

 production were likewise above the basal requirements. A total incre- 

 ment of 13.5 grams was found in both carbon-dioxide production 

 and oxygen consumption, and in heat production of 44 calories. While 

 in all probability the addition to the diet of the small amount of carbo- 

 hydrate in bread affected slightly the carbon-dioxide production, 

 nevertheless the ingestion of the beefsteak was undoubtedly the main 

 cause of the increment noted with all three factors. 



TABLE 207. F. M. M., January 11, 1910. Sitting. (1-hour periods.) 



Beefsteak and bread: 



Amounts, 246 grams beefsteak, 50 grams bread; nitrogen, 10.79 grams; total energy, 574 cats. 



Fuel value: Total, 480 cals. ; from protein, 58 p. ct. ; from fat, 20 p. ct.; from carbohydrates, 

 22 p. ct. 



Nitrogen in urine, 0.52 gram per hour. 1 

 Basal values (January 31 to February 19, 1910): CO2, 26.5 grams; Oj, 23 grams; heat, 2 80 cals. 



'Nitrogen in an earlier sample for one-half hour before food and 2j hours after food \va,s 1.11 

 grams per hour. 



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



F. M. M., January 12, 1910. The amounts of both beefsteak and 

 bread eaten before this experiment were somewhat smaller than on the 

 previous day, being 199 grams and 38 grams, respectively, with a 

 nitrogen content of 8.91 grams. There was a marked increase in the 

 carbon-dioxide production in the first two periods, which was possibly 

 due in part to the carbohydrate material. The significant increase in 

 the oxygen consumption and heat production also occurred in the first 

 two periods. It would appear, therefore, from this experiment that 

 the influence of the beefsteak and bread upon the metabolism was 

 practically at an end at the conclusion of the second 1-hour period. 

 The nitrogen excretion was measurably greater than in the first experi- 

 ment of the series, indicating a larger katabolism of protein. The 

 results of the experiment are given in table 208. 



F. M. M.. January 14, 1910. With 201 grams of beefsteak only 24 

 grams of bread were eaten in the experiment on this date, correspond- 



