MOUTH- AND NOSE-BREATHING, TISSOT APPARATUS. 185 

 STATISTICS OF EXPERIMENTS. 



J. K. M., June 13, ^#. Nosepieces, 3 periods; mouthpiece, 3 periods; 

 periods with nosepieces and mouthpiece alternating. In first two periods, 

 nosepieces tested for tightness with soapsuds. Respiration-rate fairly regular 

 in all periods. Range of pulse-rate, 4 to 10 beats. Average barometric 

 pressure, 752.1 mm.; average temperature of air in apparatus, 22.5 C. 



/. K. M., June 18, 1912. Nosepieces, 3 periods; mouthpiece, 3 periods; 

 periods with nosepieces and mouthpiece alternating. Range of pulse-rate 5 

 to 8 beats. Respiration-rate regular in all periods. Average barometric 

 pressure, 753 mm.; average temperature of air in apparatus, 23 C. 



J. B. T., June 15, 1912. Nosepieces, 3 periods; mouthpiece, 3 periods; 

 periods with nosepieces and mouthpiece alternating. Subject preferred nose- 

 pieces. Pulse-rate ranged from 4 to 7 beats per minute. Respiration-rate 

 regular in all periods. Average barometric pressure, 762.4 mm.; average 

 temperature of air in apparatus, 18.3 C. 



K. H. A., June 19, 1912. Nosepieces, 3 periods; mouthpiece, 3 periods; 

 periods with nosepieces and mouthpiece alternating. Subject preferred nose- 

 pieces. Range in pulse-rate 5 to 7 beats. Average barometric pressure, 

 756.1 mm.; average temperature of air in apparatus, 22.9 C. 



K. H. A., June 22, 1912. Nosepieces, 3 periods; mouthpiece, 3 periods; 

 periods with nosepieces and mouthpiece alternating. Subject said that his 

 mouth became dry in periods with mouthpiece and that he preferred nosepieces 

 to mouthpiece; in second period with nosepieces, was a little drowsy. Pulse- 

 rate varied, with a range as high as 8 beats per minute in some periods. 

 Respiration-rate very regular. Average barometric pressure, 763.8 mm.; 

 average temperature of air in apparatus, 25.6 C. 



DISCUSSION OF RESULTS. 



The results of the five experiments comparing the respiratory 

 exchange with mouth- and nose-breathing on the Tissot apparatus are 

 given in table 31. On the whole the averages show that the respira- 

 tory exchange with the two types of breathing does not differ markedly. 

 The carbon-dioxide production is 6 c.c. higher and the respiratory 

 quotient is 0.025 higher with the mouth-breathing than with the nose- 

 breathing. The averages for the other factors are practically identical. 



