134 



COMPARISONS OF RESPIRATORY EXCHANGE. 



piration in first two periods uniform and regular. In third period somewhat 

 irregular, with a number of pauses and shallow respirations; in this period he 

 was drowsy and seemed to be nearly asleep. With the Zuntz-Geppert appara- 

 tus respiration somewhat irregular, as shown by the 

 pneumograph record, the position of the chest varying 

 at different times. There were also a number of pauses 

 in the respiration. Average barometric pressure, 

 770 mm.; average temperature of air in the spiro- 

 meter unit, 21.1 C.; in Zuntz-Geppert apparatus, 

 19.9 C. The preliminary ventilation by minutes 

 preceding the two periods with the Zuntz-Geppert 

 apparatus is shown herewith. 

 H. B. L., February 20, 1912. Spirometer unit, 4 



periods; Zuntz-Geppert apparatus, 3 periods; periods with each apparatus in 



series. Nosepieces used with both forms of apparatus. In the periods with 



the Zuntz-Geppert apparatus subject was 



drowsy and in one of them he was asleep. 



Of the two forms of apparatus he preferred 



the spirometer unit, as he found it easier 



to breathe with this apparatus. He was 



unable to tell when the three-way valve 



was thrown, as he detected no difference 



between the room air and the air in the 



ventilating circuit. Pulse-rate had wide 



range in all periods, varying as much as 



10 beats per minute. Respiration with 



both apparatus very uniform. Average barometric pressure, 757.5 mm.; 



average temperature of air in spirometer unit, 20.2 C; in Zuntz-Geppert 



apparatus, 18.6 C. The preliminary ventilation by minutes preceding the 



three periods with the Zuntz-Geppert apparatus is shown herewith. 



H. B. L., February 21, 1912. Subject had light breakfast; experiment began 

 12 h 49 m p. m. Zuntz-Geppert 



apparatus, 4 periods; spirom- 

 eter unit, 4 periods ; apparatus 

 alternating for the most part. 

 Pulse-rate varied somewhat in 

 individual periods. Respiration 

 uniform in each period. Aver- 

 age barometric pressure, 757.3 

 mm.; average temperature of 

 air in spirometer unit, 20.1 C. ; 

 in Zuntz-Geppert apparatus, 

 16.9 C. The preliminary ventilation by minutes preceding the four periods 

 with the Zuntz-Geppert apparatus is shown herewith. 

 H. B. L., February 28, 1912 Subject had light 

 breakfast at about 7 a.m. ; experiment began 2 h 10 m 

 p. m. Spirometer unit, 3 periods; Zuntz-Geppert 

 apparatus, 2 periods; apparatus alternated. Pulse- 

 rate varied in most of the periods. With spirometer 

 unit, respiration varied, being regular in the first half 

 of period but apnoeic in character in the last part of 

 the period. This was especially apparent in the first 

 and second periods. With the Zuntz-Geppert appa- 



