164 COMPARISONS OF RESPIRATORY EXCHANGE. 



J. B. T., June 27, 1912. — Spirometer unit, 3 periods; Douglas apparatus, 

 3 periods; preliminary period, 34 minutes; apparatus alternated. Subject 

 lying on couch; pneumatic nosepieces with both apparatus and rubber-flap 

 valves and small bag with Douglas apparatus. Subject said with Douglas 

 method it was difficult to exhale. Pressure in bag at end of experiment 

 7 to 8 mm. of water. Both pulse-rate and respiration-rate uniform in all 

 periods. Average barometric pressure and temperature of air in apparatus 

 were: Spirometer unit, 767.9 mm. and 22.8° C, respectively; Douglas appa- 

 ratus, 767.8 mm. and 22.8° C, respectively. 



J. K. M., July 1, 1912. — Spirometer unit, 3 periods; Douglas apparatus, 



2 periods; preliminary period, 57 minutes; first two periods with spirometer 

 unit, then apparatus alternated. Subject lying on couch; pneumatic nose- 

 pieces with both apparatus, and rubber-flap valves and small bag with Douglas 

 apparatus. Subject stated that he noted no difference between methods. 

 Pressure on bag at end of experiment 6 mm. Both pulse-rate and respiration- 

 rate fairly uniform. Average barometric pressure and temperature of air in 

 apparatus were: Spirometer unit, 767.0 mm. and 21.3° C, respectively; 

 Douglas apparatus, 767.1 mm. and 22.4° C, respectively. 



J. K. M., July 3, 1912. — Spirometer unit, 3 periods; Douglas apparatus, 



3 periods; preliminary period, 57 minutes; apparatus alternated. Subject 

 lying on couch; nosepieces used with both apparatus, and rubber-flap valves 

 and small bag with Douglas apparatus. Subject said that there was a slight 

 resistance to exhaling. Pressure on bag at end of experiment 6 mm. of water. 

 Subject drowsy in first two periods with spirometer unit; wide awake in last 

 period. In last period with Douglas apparatus he had a great desire to get 

 through with the experiment. Pulse-rate and respiration-rate both uniform. 

 Average barometric pressure and temperature of air in apparatus were: 

 Spirometer unit, 765.8 mm. and 21.6° C, respectively; Douglas apparatus, 

 765.9 mm. and 22.3° C, respectively. 



S. A. R., July 20, 1912. — Douglas apparatus, 3 periods; spirometer unit, 



3 periods; apparatus alternated. Subject lying on couch; pneumatic nose- 

 pieces with spirometer unit; mouthpiece, rubber-flap valves and large bag with 

 Douglas apparatus. Subject thought Douglas method easier than spirometer 

 unit. Pressure in bag at end of experiment 4 to 5 mm. of water. Pulse-rate 

 comparatively uniform. In all periods there was a tendency to apncea in 

 respiration, more particularly with Douglas method. Average barometric 

 pressure and temperature of air in apparatus were: Spirometer unit, 767.4 

 mm. and 21.1° C, respectively; Douglas apparatus, 767.6 mm. and 19.8° C, 

 respectively. 



M. J. S., July 19, 1912. — Spirometer unit, 2 periods; Douglas apparatus, 

 2 periods; preliminary period, 2 hours; apparatus alternated. Subject lying 

 on couch; glass nosepieces with spirometer unit and mouthpiece with special 

 moistener with Douglas apparatus; rubber-flap valves and large bag with 

 Douglas apparatus. Pulse-rate varied somewhat in first period with each 

 apparatus. Respiration irregular in periods with spirometer unit, particularly 

 in the last few minutes. The type of respiration is shown in figure 45. Aver- 

 age barometric pressure and average temperature of air in apparatus were: 

 Spirometer unit, 757.9 mm. and 20.8° C, respectively; Douglas apparatus, 

 758.4 mm. and 21.7° C, respectively. 



M. J. S., July 22, 1912. — Douglas apparatus, 4 periods; spirometer unit, 



4 periods; preliminary period, 52 minutes; apparatus alternated. Subject 

 lying on couch; pneumatic nosepieces with spirometer unit, mouthpiece with 

 Douglas apparatus; mica-flap valves and large bag with Douglas apparatus. 

 Intake valve arranged so that flap was horizontal, in order to be sure that it 



