306 FOOD INGESTION AND ENERGY TRANSFORMATIONS. 



INGESTION OF MIXED NUTRIENTS. 



Studies with a single mixed nutrient were made with but one food 

 material, this being whole milk. In addition, two experiments were 

 made in which the milk was combined with one other food material, and 

 in a considerable number of experiments the metabolism was measured 

 after a diet such as would be taken in one or more ordinary meals. 



MILK. 



No other single food material contains the three important nutrients, 

 protein, fat, and carbohydrate, in such relatively well-balanced propor- 

 tions as whole milk does. Three calorimeter experiments and one 

 respiration experiment were made to study the effect upon the metab- 

 olism of the ingestion of milk. Statistical data not included in the 

 tables or in the discussion of the experiments are as follows : 



H. R. D., 8 h 40 m a. m. to 4 h 40 m p. m., March 21, 1908. 59.2 kilograms. 

 During experiment sat very quietly, reading about four-fifths of time; very 

 drowsy at 10 a. m. Urinated 6 h 50 m a. m., Il h 40 m a. m., and 4 h 55 m p. m.; 

 defecated (after enema) about 7 h 20 m a. m. Body-temperature: 36.95, 

 36.69, 36.71, 36.71, 36.69 C. Pulse rate, 63; respiration rate, 19. 



A, L. L., 8 h 40 m a. m. to 4 h 40 m p. m., March 22, 1906. 68.3 kilograms. 

 Urinated 7 h 20 m a. m. and 4 h 57 m p. m. Sat very quietly reading; not sleepy 

 except near end of experiment. Body- temperature : 36.72, 36.65, 36.70, 

 36.64, 36.53 C. Pulse rate, 61; respiration rate, 19. 



A. H. M., 8 h 30 m a. m. to 4 h 30 m p. m., March 23, 1906. 67.0 kilograms. 

 Urinated 6 h 30 ra a. m., 12 h 40 m p. m., 4 h 45 m p. m. Read very little, and sat 

 quiet in chair; drowsy, especially in afternoon. Body-temperature: 36.59, 

 36.44, 36.42, 36.44, 36.33 C. Pulse rate, 53; respiration rate, 16. 



H. F. T., 10 h 21 m a. m. to 2 h 15 m p. m., July 14, 1911. 57.9 kilograms. 

 Milk experiment on this day preceded by observations of the gaseous exchange 

 8^ hours after ingestion of beefsteak. (See page 286.) Tired and restless in 

 fifth period. Nitrogen in urine per hour 7 a. m. to 10 h 40 m a. m., 0.69 gram; 

 10 h 40 m a. m. to 2 h 20 ra p. m., 0.72 gram. 



CALORIMETER EXPERIMENTS. 



In the calorimeter experiments with milk, a study was made of the 

 influence of approximately 600 grams of whole milk, in which 19 per 

 cent of the fuel value came from protein, 52 per cent from fat, and 29 

 per cent from carbohydrates. These experiments were carried out 

 with three subjects on successive days with the Middletown respiration 

 calorimeter. As was usual with these earlier experiments, the only 

 basal values obtainable were determined several days or weeks before 

 or after the food study and hence are not ideal for purposes of com- 

 parison. The observations were all made in 2-hour periods. 



H. R. D., March 21, 1906. The data obtained following the inges- 

 tion of 599 grams of milk and 9 grams of lime-water, with a fuel value 

 of 444 calories, are given in table 231. These show an increment in 

 carbon-dioxide production in all of the periods, with but 1 gram in the 

 last period. The values for oxygen consumption were irregular, but 





