130 COMPARISONS OF RESPIRATORY EXCHANGE. 



Zuntz-Geppert apparatus, but the subject began breathing into the apparatus 

 as soon as the attachments were made and a sample of air was taken 1 or 2 

 minutes afterwards. 



Pulse-rate for the most part regular. Respiration irregular. Sections of 

 curves obtained in this experiment are reproduced in figure 39 to show the 

 types of respiration exhibited by this subject at different times, and also to 

 show their relation to the results. In the first period with the spirometer 

 unit, the respiration was frequently delayed. This was wholly unconscious. 

 The subject had frequently been used for experiments and was therefore accus- 

 tomed to this apparatus. In the second period, on the contrary, there was a 

 decided increase in the ventilation of the lungs and the effect upon the results 

 is clearly shown. Again in the third period with the same apparatus, the respi- 

 ration was apnceic. In the first period with the Zuntz-Geppert apparatus, 

 the respiration was not distinctively apnceic and the cause for the low carbon- 

 dioxide production is not so apparent as with the other apparatus. Unfortu- 



FIG. 39. Types of respiration of subject H. F. T. with the spirometer unit on January 18, 1912. 

 Three-fifths original size. 



Upper curve, third period; lower curve, sixth period; time lines, minutes. 



nately the recording apparatus was not adjusted to show the differentiation 

 between the types very clearly. In the last period of the experiment (with 

 the spirometer unit), the respiration was very regular. Average barometric 

 pressure, 766.0 mm. ; average temperature of air with the spirometer unit, 

 22.3 C.; with the Zuntz-Geppert apparatus, 20.7 C. 



H. F. T., January 19, 1912. Spirometer unit, 4 periods; Zuntz-Geppert 

 apparatus, 3 periods; apparatus alternated. No preliminary ventilation was 

 recorded with the Zuntz-Geppert apparatus. Respiration again varying in 

 character; with spirometer unit, more or less apnceic in first period of experi- 

 ment, markedly apnceic in third period, and for the most part uniform in fifth 

 and seventh periods; with Zuntz-Geppert apparatus, apnceic throughout 

 second period of experiment, with slow rate and total ventilation of lungs 

 slow; long pauses between respirations in fourth period; also many long pauses 



