DOUGLAS AND BENEDICT METHODS. 



165 



would close properly during expiration. The expiration valve was nearly 

 horizontal. During first two or three minutes with Douglas method the 

 intake valve did not appear to close properly, as the bag fell slightly at the 

 beginning of each inspiration; the subject also stated that the air did not 

 seem pure, except when he inspired deeply. In third period with Douglas 

 apparatus the intake valve was placed at the end of a long rubber tube, so 

 that it hung below the couch and was vertical. The subject stated that it 

 was very easy to breathe with this arrangement of the valve. Pulse-rate 

 very uniform. Tendency toward deep respiration at end of second period 

 with Douglas apparatus; deeper respirations than normal in other periods 



i i i i 



Fig. 45. — Types of respiration of subject M. J. S. at end of second and fourth periods with the 

 spirometer unit on July 19, 1912. Time line, minutes. Original size. 



with this apparatus. Respirations perfectly normal with spirometer unit. 

 Average barometric pressure and average temperature of air in apparatus 

 were: Spirometer unit, 756.3 mm. and 22.5° C, respectively; Douglas appa- 

 ratus, 756.2 mm. and 22.7° C, respectively. 



M. J. S., July 24, 1912. — Douglas apparatus, 3 periods; spirometer unit, 

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

 lying on couch; with Douglas method. Tissot valves, glass nosepieces, and 

 large bag; with spirometer unit, pneumatic nosepieces. Subject preferred 

 Douglas apparatus, as glass nosepieces easier to breathe through. Subject 



