BENEDICT APPARATUS, INCREASED DEAD SPACE. 



213 



distressed him, but otherwise he was perfectly comfortable. Pulse-rate very 

 uniform in all of the periods. Respiration uniform in all periods, both as to rate 

 and character. Average barometric pressure, 754.7 mm.; average tempera- 

 ture of air in apparatus, 18.5° C. 



STATISTICS OF EXPERIMENTS WITH INCREASE IN DEAD SPACE OF 224 C.C. 



J. K. M., December 3, 1912. — Without dead space, 3 periods; with dead 

 space, 3 periods; periods with and without additional dead space alternating. 

 New form of glass nosepieces used in normal periods; pneumatic nosepieces in 

 periods with additional dead space. Subject very drowsy in normal periods. 

 Pulse-rate somewhat variable in first four periods; uniform in last two periods. 

 Respiration uniform in all periods, especially in the periods with the increased 

 dead space. Average barometric pressure, 763.3 mm.; average temperature 

 of air in apparatus, 21.1° C. 



J. B. T., December 7, 1912. — Without dead space, 3 periods; with dead space, 

 3 periods; periods with and without additional dead space alternating. Pneu- 

 matic nosepieces used. Pulse-rate in first, second, third, and sixth periods 

 uniform; in fourth period varied from 71 to 78; in fifth period, from 74 to 85. 

 Respiration very uniform in all periods, but subject said he had difficulty in 

 breathing throughout the first period and again in the middle of the last period. 

 Sections of the respiration curves are given in figures 70 and 71. Average 

 barometric pressure 759.7 mm. ; average temperature of air in apparatus 20.9° C. 



Fig. 71. — Type of respiration of subject J. B. T. without additional dead space on 

 December 7, 1912. Original size. 



DISCUSSION OF RESULTS. 



The results of the comparison experiments with and without addi- 

 tional dead space in the spirometer unit are given in table 39. A study 

 of these results shows but little, if any, difference in the two types of 

 breathing with an additional dead space of not more than 224 c.c. 



