146 COMPARISONS OF RESPIRATORY EXCHANGE. 



barometric pressure, 763.3 mm.; average temperature of air in apparatus, 

 19.7 C. 



H. F. T., September 6, 1911. Tension-equalizer unit, 4 periods; Tissot 

 apparatus, 3 periods; periods with tension equalizer and Tissot apparatus in 

 series. With Tissot apparatus, 200-liter spirometer. Range in pulse-rate 

 about 4 beats per minute in each period. Respiration-rate uniform in entire 

 series. Average barometric pressure, 752.3 mm.; average temperature of 

 air in apparatus, 24 C. 



H. F. T., September 13, 1911. Tissot apparatus, 5 periods; tension-equalizer 

 unit, 6 periods; apparatus usually alternated. Pneumatic nosepieces with 

 both apparatus; 200-liter spirometer with Tissot apparatus. Pulse-rate and 

 respiration-rate fairly uniform in the individual periods. Average barometric 

 pressure, 760.6 mm.; average temperature of air in apparatus, 20.5 C. 



H. F. T., September 15, 1911. Tension-equalizer unit, 6 periods; Tissot 

 apparatus, 6 periods; preliminary period, 13 minutes; apparatus alternated. 

 With Tissot apparatus, 200-liter spirometer. Nosepieces inserted approxi- 

 mately 5 minutes before periods with Tissot apparatus began. Both pulse- 

 rate and respiration-rate comparatively uniform. In third period with 

 tension-equalizer unit, too much oxygen was admitted and the subject accord- 

 ingly exhaled against some pressure; the respiration was in consequence 

 slightly increased in volume. Average barometric pressure, 766.1 mm.; 

 average temperature of air in apparatus, 20.0 C. 



H. F. T., September 18, 1911. Tissot apparatus, 4 periods; tension-equalizer 

 unit, 4 periods; apparatus alternated. With Tissot apparatus, 200-liter 

 spirometer. Pulse-rate uniform, except that the range in the last period with 

 each apparatus was about 4 beats per minute. Respiration-rate fairly uni- 

 form, with occasional pauses at end of expiration. Average barometric pres- 

 sure, 762.9 mm.; average temperature of air in apparatus, 20.9 C. 



H. F. T., September 22, 1911. Tension-equalizer unit, 6 periods; Tissot 

 apparatus, 6 periods; apparatus alternated. With Tissot apparatus, 200-liter 

 spirometer. Both pulse-rate and respiration-rate regular. Average baro- 

 metric pressure, 763.6 mm.; average temperature of air in apparatus, 21.9 C. 



K. H. A., August 5, 1911. Tension-equalizer unit, 6 periods; Tissot appa- 

 ratus, 2 periods; all but fourth and seventh periods with tension-equalizer 

 unit. Pneumatic nosepieces with tension-equalizer unit; mouthpiece and 50- 

 liter spirometer with Tissot apparatus. Both pulse-rate and respiration-rate 

 uniform. Average barometric pressure, 762.0 mm., average temperature of 

 air in apparatus, 23.1 C. 



DISCUSSION OF RESULTS. 



The results for the periods in all of the experiments and the averages 

 for each apparatus, both for the individual experiments and for all 

 of the periods in the study, are given in table 21. It will be seen that 

 the grand averages of the values obtained with both apparatus are 

 practically identical. These are as follows, the values for the tension- 

 equalizer unit preceding: Carbon-dioxide elimination, 165 c.c. and 167 

 c.c. ; oxygen absorption, 193 c.c., and 194 c.c. ; respiratory quotient, 0.855 

 and 0.860; pulse-rate, 47.0 and 48.0; respiration-rate, 10.1 and 10.2. 

 The average values obtained with the Tissot apparatus for the ventila- 

 tion of the lungs is 4.26 liters; volume per respiration, 503 c.c. 



