196 COMPARISONS OF RESPIRATORY EXCHANGE. 



period with the Mueller valves and second period with spirometer unit. Parts 

 of the curves for these two periods are given in figures 52 and 53. Average 

 barometric pressure, 773.8 mm. ; average temperature of air in apparatus with 

 Mueller valves, 20.6 C.; with spirometer unit, 21.1 C. 



J. J. G., March 19, 1918. Mueller valves and Tissot spirometer, 3 periods: 

 spirometer unit, 3 periods; preliminary period, 1 hour 5 minutes; periods with 

 two methods alternated. Subject arose and urinated at 9 h 25 m a. m.; drowsy 

 in second period with spirometer unit. The values for the carbon-dioxide 

 production and oxygen consumption in the first period with Mueller valves 

 are not included in averages, as there were indications that the sample of air 

 was contaminated. Pulse-rate uniform in all periods. Respiration-rate 

 before experiment, 21 per minute; during experiment very regular in type and 

 rate. Average barometric pressure for Mueller valves, 772.5 mm., and for 

 spirometer unit, 771.8 mm.; average temperature of air in apparatus with 

 Mueller valves, 18.7 C.; with spirometer unit, 19.6 C. 



J. J. G., March 20, 1913. Spirometer unit, 4 periods; Mueller valves and 

 Tissot spirometer, 4 periods; preliminary period, 29 minutes; periods with two 

 methods alternated. Pulse-rate regular throughout experiment. Respiration- 

 rate before experiment, 19 per minute; during experiment, fairly regular in 

 depth. Average barometric pressure, 763.7 mm, ; average temperature of air 

 in apparatus, 16.5 C. with Mueller valves and 17.8 C. with spirometer unit. 



FIG. 52. Types of respiration of subject W. J. T. as shown by the pneumograph in the first two 

 periods with the Mueller valves and Tissot spirometer on March 29, 1913. Time line, min- 

 utes. Four-fifths original size. 



FIG. 53. Type of respiration of subject W. J. T. as recorded from the spirometer bell in the 

 second period with the spirometer unit on March 29, 1913. Time line, minutes. Three- 

 fourths original size. 



J. J. G., April 2, 1913. Spirometer unit, 4 periods; Mueller valves, 3 

 periods; preliminary period, 54 minutes; periods with each method in series. 

 Pulse-rate fairly regular. Respiration-rate before experiment averaged 17 

 per minute; rate and type during experiment very regular. Average baro- 

 metric pressure, 754.6 mm. ; temperature of air in apparatus with spirometer 

 unit, 21.6 C.; with Mueller valves, 19.5 C. 



DISCUSSION OF RESULTS. 



The results of the individual experiments in this series are given in 

 table 35. The average of all of the experiments shows a slight differ- 

 ence between the results with the two methods, the carbon-dioxide 

 elimination and oxygen consumption being higher with the Mueller 

 valves than with the spirometer unit, although the average respiratory 



