172 



COMPARISONS OF RESPIRATORY EXCHANGE. 



lower with the Douglas method than with the spirometer unit and some 

 of the experiments also show lower values for the oxygen consumption. 

 In the majority of the experiments the pulse-rate, the respiration-rate, 

 and the ventilation per minute are likewise lower with the Douglas 

 method. 



In the experiments with the larger bag, i. e., those following July 4, 

 1912, the fluctuations between the averages are both plus and minus. 

 In general they are all comparatively consistent in their differences — 

 that is to say, when there is a smaller carbon-dioxide output with the 



» 10 II 12 13 14 15 O I 



pza cs.ni or VAhiA2i.im 



4 5 6 1 a Si 10 II 12 13 I 4 li 



Fia. 46. — Probability curves for the series of comparison experiments with the spirometer unit 



and the Douglas method. 



The ordinates indicate the percentage of the total number of periods and the abscissae the 

 percentage of variation from the average. 



Douglas apparatus, there is also a smaller oxygen intake, this being 

 true in five cases out of seven. In general, the results are more satis- 

 factory with the larger bag than with the smaller. 



The probability curves are given in figure 46, which show that as a 

 whole the results with the spirometer unit are much more uniform so 

 far as the carbon-dioxide and oxygen are concerned than are those with 

 the Douglas method; on the contrary, the experiments with the Douglas 

 method show much more uniform respiratory quotients. The other 

 factors have about the same degree of uniformity. 



