MUELLER AND TISSOT VALVES. 201 



STATISTICS OF EXPERIMENTS. 



W. J. T., April 5, 1913. — Mueller valves, 4 periods; Tissot valves, 3 periods; 

 preliminary period, 43 minutes; periods with two types of valves in series. 

 Counterpoise tube three-quarters full of water; no water running in siphon 

 tube. Subject stated he noted no difference in inspiration and expiration with 

 Mueller valves. Pulse-rate regular in all periods. Average respiration-rate 

 in preliminary period, 18 to 19 per minute. Respiration-rate irregular in all 

 periods, particularly in first period with Tissot valves. Average barometric 

 pressure, 758.4 mm.; average temperature of air in apparatus, 16.2° C. 



W.J. T., April 12, 1913. — Mueller valves, 3 periods; Tissot valves, 3 periods; 

 preliminary period, 36 minutes; periods with two types of valves alternating. 

 Counterpoise of spirometer two-thirds full of water; no water running in 

 siphon tube. Subject stated that the breathing was easier with the Tissot 

 valves than with the Mueller valves. He was drowsy at times. Pulse-rate 

 fairly uniform. Average respiration-<rate in preliminary period, 20 per minute ; 

 regular throughout each period; character of respiration can not be distin- 

 guished, as the pneumograph did not work properly. Average barometric 

 pressure, 760.7 mm.; average temperature of air in apparatus, 16.7° C. 



W. J. T., April 26, 1913. — Mueller valves, 2 periods; Tissot valves, 3 

 periods, preliminary period, 42 minutes; periods with two types of valves 

 alternating. Subject stated that he found it easier to breathe through 

 Mueller valves than through the Tissot valves. Pulse-rate fairly uniform. 

 Normal respiration-rate before experiment, 20 per minute. Respiration- 

 rate during experiment regular in rate and character. Average barometric 

 pressure, 762.9 mm. ; average temperature of air in apparatus, 19.4° C. 



J. J. G., April 8, 1913. — Tissot valves, 3 periods; Mueller valves, 2 periods; 

 preliminary period, 1 hour 20 minutes; periods with two types of valves in 

 series. Pulse-rate very uniform throughout experiment. Normal respiration- 

 rate before experiment, 17 per minute, records being taken for 1 hour previous 

 to experimental period. Respiration in experiment uniform in rate; character 

 could not be distinguished, as pneumograph did not work properly. Baro- 

 metric pressure, 763.1 mm.; average temperature of air in apparatus, 15.6° C. 



J. J. G., April 15, 1913. — Mueller valves, 3 periods; Tissot valves, 3 periods; 

 preliminary period, 1 hour; periods with two types of valves alternating. 

 Pulse-rate uniform in all of the periods. Average normal respiration-rate 

 before experiment, 19 per minute; during experiment uniform in each period. 

 Average barometric pressure, 760.5 mm. ; average temperature of air in appa- 

 ratus, 17.0° C. 



J. J. G., April 22, 1913. — Mueller valves, 3 periods; Tissot valves, 3 periods; 

 preliminary period, 30 minutes; periods with two types of valves alternating. 

 Subject stated that he could see no difference in the two types of valves. 

 Pulse-rate fairly uniform throughout experiment. Average normal respira- 

 tion before experiment, 19 per minute; during experiment, fairly uniform in 

 rate and character in each period. Average barometric pressure, 763.8 mm. ; 

 average temperature of air in apparatus, 17.4° C. 



J. H. H., April 18, 1 913.— Mueller valves, 3 periods; Tissot valves, 3 

 periods; preliminary period, 16 minutes; periods with two types of valves 



Fig. 55. — Type of respiration of subject J. H. H. in the fourth and fifth periods on April 18, 1913. 

 Upper curve, Mueller valves; lower curve, Tissot valves. Original size. 



