122 FOOD INGESTION AND ENERGY TRANSFORMATIONS. 



respiration apparatus were not continuous, there being intermissions 

 varying in length according to the conditions of experimenting, food 

 material used, etc. It was usual to make a 15-minute observation 

 every half hour during the experimental period, but the intermissions 

 were often much longer. The intermissions with the Tissot apparatus 

 were usually brief. As a rule, the subject lay on the couch during the 

 intermissions with both apparatus and was more or less quiet. 



In the Middletown experiments the movements made by the subject 

 were recorded by an observer, but in nearly all of the Boston experi- 

 ments the degree of muscular repose was shown by some form of graphic 

 record. In many of the calorimeter experiments observations were 

 made of the body-temperature; the data recorded were secured per 

 rectum, by means of an electrical-resistance thermometer. 



Records of the pulse rate were obtained with the Fitz pneumograph 

 in the Middletown experiments, but in the calorimeter experiments in 

 Boston and in the experiments with respiration apparatus the Bowles 

 stethoscope was used, the counts being made by a special observer. 



Records of the respiration rate were secured in practically all of 

 the Middletown and Boston calorimeter experiments and in the experi- 

 ments with the tension-equalizer form of the universal respiration 

 apparatus by means of the Fitz pneumograph. In the experiments 

 with the respiration apparatus the pneumograph was connected with a 

 kymograph, thus giving graphic records of the respiration. In the obser- 

 vations with the spirometer form of the universal respiration apparatus, 

 the graphic record of the respiration was provided by a mechanical de- 

 vice attached to the spirometer instead of by the Fitz pneumograph. 



In several groups of the Boston experiments, i. e., those with water, 

 coffee, and beef tea, records of the blood pressure were obtained with 

 the Erlanger sphygmomanometer. 



Table 49 gives a list of the food experiments, grouped according to 

 the apparatus and diet used. It shows that 59 experiments were made 

 with the respiration calorimeter in Middletown, 41 experiments with 

 the chair calorimeter and 3 experiments with the bed calorimeter in 

 Boston. In the experiments in which only the respiratory exchange 

 was determined, 78 experiments were made with the universal respira- 

 tion apparatus and 9 experiments with the Tissot apparatus. The 

 research included, in all, 190 experiments, i. e., 15 chewing experiments, 

 11 experiments with water, 8 with coffee, 13 with beef tea, 65 with 

 carbohydrates, 15 with a fat diet, 44 with a protein diet, and 19 with 

 mixed nutrients. 



The composition and fuel value of the food materials used in the 

 experiments are shown in table 50. The values are, for the most part, 

 directly determined or are computed from determined values. The 

 composition of the mixed diets may be found in the section describing 

 the experiments with mixed nutrients. 1 



'See table 235, p. 310. 



