86 COMPARISONS OF RESPIRATORY EXCHANGE. 



latter method was used unless otherwise stated. In the later calor- 

 imeter experiments no record was obtained of the respiration-rate. 



Graphic records of the muscular activity were secured with the chest 

 pneumograph, with the occasional addition of the hip pneumograph, 

 or by the special form of bed-rest previously referred to. 1 In the longer 

 calorimeter experiments absolute muscular repose for the whole time 

 was difficult to obtain and the subjects were inclined to fall asleep. 

 They were not required to keep awake in the earlier experiments with 

 this apparatus, but later were asked to do so, if possible, and requested 

 not to change the position more than once in a period. 



Both laboratory assistants and medical students were used as subjects, 

 the latter being employed more particularly in the later comparisons. 

 While the medical students were unfamiliar with the two apparatus, this 

 proved to be no detriment to the experiments, as they quickly became 

 accustomed to the apparatus and the routine. The statistics of the 36 

 experiments are given in the following pages. The maj ority of the experi- 

 ments with the bed calorimeter were carried out by Mr. L. E. Emmes. 



STATISTICS OF EXPERIMENTS. 



F. G. B., March 1, 1909. Bed calorimeter, two 1-hour periods; tension- 

 equalizer unit, three 8- to 10-minute periods; preliminary period, 1 hour 21 

 minutes. Mouthpiece used with tension-equalizer unit. Pulse-rate taken 

 by subject in calorimeter, by observer (three counts in each period) with 

 tension-equalizer unit. Respiration-rate with calorimeter recorded by chest 

 pneumograph; with tension-equalizer unit counted by observer. Subject 

 urinated in calorimeter at 8 h 50 m a. m., turned over on his side twice during 

 each period. Awake and fairly quiet with both apparatus, except as noted. 



F. G. B., March 2, 1909. Bed calorimeter, five 30-minute periods; tension- 

 equalizer unit, three 10-minute periods; preliminary period, 1 hour 1 minute. 

 Mouthpiece used with tension-equalizer unit. Pulse-rate counted few times 

 by subject in calorimeter; by observer with tension-equalizer unit. Respira- 

 tion-rate recorded by chest pneumograph with calorimeter; observed by assis- 

 tant with tension-equalizer unit; two counts with each apparatus. Subject 

 turned over twice in calorimeter, urinating immediately after the beginning 

 of the first period; otherwise quiet and awake with both apparatus. 



F. G. B., November 15, 1910. Bed calorimeter, two 1-hour periods; tension- 

 equalizer unit, three 15-minute periods; preliminary period, 1 hour 4 minutes. 

 Mouthpiece used with tension-equalizer unit. Pulse-rate taken by subject 

 in calorimeter. Considerable activity during first period with calorimeter 

 and subject turned over on side once during second period; quiet in periods 

 with tension-equalizer unit. Both pulse- and respiration-rates regular. 



J. A. R., March 20, 1909. Tension-equalizer unit, three 10-minute periods; 

 bed calorimeter, two 1-hour periods. Pneumatic nosepieces used with tension- 

 equalizer unit. Pulse-rate counted by observer from stethoscope with both 

 apparatus, several counts in each period; respiration-rate recorded by chest 

 pneumograph. Subject quiet and awake with both apparatus. 



T. M. C., March 23, 1909. Subject had a small cup of clear coffee at 6 a. m.; 

 experiment began at 8 h 5 m a. m. Three series: Tension-equalizer unit, four 

 10-minute periods; bed calorimeter, two 1-hour periods; finally, tension- 



'See p. 84. 



